U.S. patent application number 15/623603 was filed with the patent office on 2017-12-21 for high performance surfactant free latexes for improved water resistance.
This patent application is currently assigned to RHODIA OPERATIONS. The applicant listed for this patent is RHODIA OPERATIONS. Invention is credited to Tiffany CHEN, Pierre-Emmanuel DUFILS, Adnan SIDDIQUI, David James WILSON.
Application Number | 20170362425 15/623603 |
Document ID | / |
Family ID | 60660823 |
Filed Date | 2017-12-21 |
United States Patent
Application |
20170362425 |
Kind Code |
A1 |
SIDDIQUI; Adnan ; et
al. |
December 21, 2017 |
High Performance Surfactant Free Latexes for Improved Water
Resistance
Abstract
Coatings and other applications containing a latex with modified
surface properties obtainable by methods of adding a water soluble
amphiphilic copolymer in a aqueous dispersion of a water-insoluble
polymer obtained from ethylenically unsaturated monomers.
Inventors: |
SIDDIQUI; Adnan; (Tenafly,
NJ) ; DUFILS; Pierre-Emmanuel; (Paris, FR) ;
WILSON; David James; (Coye la Forte, FR) ; CHEN;
Tiffany; (Newark, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
RHODIA OPERATIONS |
Paris |
|
FR |
|
|
Assignee: |
RHODIA OPERATIONS
Paris
FR
|
Family ID: |
60660823 |
Appl. No.: |
15/623603 |
Filed: |
June 15, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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62350374 |
Jun 15, 2016 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08F 220/06 20130101;
C08F 220/54 20130101; C08L 2201/52 20130101; C09D 7/20 20180101;
C08F 212/08 20130101; C08F 220/06 20130101; C08F 220/06 20130101;
C08F 220/1804 20200201; C08F 212/08 20130101; C08F 218/08 20130101;
C08F 220/06 20130101; C08F 218/08 20130101; C08F 220/1804 20200201;
C08F 220/54 20130101; C09D 133/04 20130101; C09D 5/14 20130101;
C08F 220/06 20130101; C08F 220/1804 20200201; C08F 220/1804
20200201; C08F 220/1804 20200201; C08F 220/1804 20200201; C08F
220/54 20130101; C08L 31/04 20130101; C08F 220/54 20130101; C09D
133/00 20130101; C08F 293/005 20130101; C09D 153/00 20130101; C09D
7/63 20180101; C08F 220/54 20130101; C09D 131/04 20130101; C08F
220/06 20130101; C08F 220/06 20130101; C08F 218/08 20130101; C08F
2438/03 20130101 |
International
Class: |
C08L 31/04 20060101
C08L031/04; C09D 7/00 20060101 C09D007/00; C09D 5/14 20060101
C09D005/14; C09D 131/04 20060101 C09D131/04 |
Claims
1. An aqueous composition comprising: water; optionally, a pigment;
and a film-forming latex composition with modified surface
chemistry obtained by free-radical emulsion polymerization in the
presence: of at least one ethylenically unsaturated monomer or at
least one polymer containing residual ethylenically unsaturated
bonds, of at least one free-radical polymerization initiator, and
of at least one water-soluble and/or water-dispersible polymer of
formula (Ia) or formula (Ib):
(R.sup.11)x-Z.sup.11--C(.dbd.S)--Z.sup.12-[A]-[B]-R.sup.12 (Ia), or
(R.sup.11)x-Z.sup.11--C(.dbd.S)--Z.sup.12-[B]-R.sup.12 (Ib)
wherein: Z.sup.11 represents C, N, O, S or P, represents S or P,
R.sup.11 and R.sup.12, which may be identical or different,
represent: an optionally substituted alkyl, acyl, aryl, alkene or
alkyne group (i), or a saturated or unsaturated, optionally
substituted or aromatic carbon-based ring (ii), or a saturated or
unsaturated, optionally substituted heterocycle (iii), these groups
(1) rings (i) or heterocycles (iii) being optionally substituted
with substituted phenyl groups, substituted aromatic groups or
groups selected from: alkoxycarbonyl or aryloxycarbonyl (--COOR)
groups, carboxyl (--COOH) groups, acyloxy (--O.sub.2CR) groups,
carbamoyl (--CONR.sub.2) groups, cyano (--CN) groups, alkylcarbonyl
groups, alkylarylcarbonyl groups, arylcarbonyl groups,
arylalkylcarbonyl groups, phthalimido groups, maleimido groups,
succinimido groups, amidino groups, guanidimo groups, hydroxyl
(--OH) groups, amino (--NR.sub.2) groups, halogen groups, allyl
groups, epoxy groups, alkoxy (--OR) groups, S-alkyl groups, S-aryl
groups, alkali metal salts of carboxylic acids, alkali metal salts
of sulphonic acid, polyalkylene oxide (PEO or PPO) chains, and
quaternary ammonium salts, wherein R represents an alkyl or aryl
group, x corresponds to the valency of Z.sup.11, or alternatively x
is 0, in which case Z.sup.11 represents a phenyl, alkene or alkyne
radical, being optionally substituted with groups selected from: an
optionally substituted alkyl, acyl, aryl, alkene or alkyne group,
an optionally substituted, saturated, unsaturated, or aromatic,
carbon-based ring, an optionally substituted, saturated or
unsaturated heterocycle; an alkoxycarbonyl or aryloxycarbonyl
(--COOR) group, a carboxyl (COOH) group, an acyloxy (--O.sub.2CR)
group, a carbamoyl (--CONR.sub.2) group, a cyano (--CN) group; an
alkylcarbonyl group; an alkylarylcarbonyl group; an arylcarbonyl
group; an arylalkylcarbonyl group; a phthalimido group, a maleimido
group, a succinimido group, a amidino group, a guanidimo group, a
hydroxyl (--OH) group, an amino (--NR.sub.2) group, a halogen
group, an allyl group, an epoxy group, an alkoxy (--OR) group, a
S-alkyl group, a S-aryl group, an alkali metal salt of carboxylic
acid, an alkali metal salt of sulphonic acid, polyalkylene oxide
(PEO or PPO) chains, and quaternary ammonium salts, wherein R
represents an alkyl or aryl group; A is a monoblock, diblock or
triblock polymer comprising at least a first block which is
hydrophobic in nature; and B is a monoblock, diblock or triblock
polymer comprising at least one monomer of vinyl acetate.
2. The aqueous composition of claim 1 wherein the film-forming
latex composition with modified surface chemistry is obtained by
free-radical emulsion polymerization in the absence of a
surfactant.
3. The aqueous composition of claim 1 wherein the at least one
water-soluble and/or water-dispersible polymer of formula (Ia) or
formula (Ib) has a weight average molecular weight of from 5,000 to
7,000 Daltons.
4. The aqueous composition of claim 1 wherein the at least one
ethylenically unsaturated monomer comprises: (a) at least one first
monomer selected from: methyl (meth)acrylate, ethyl (meth)acrylate,
butyl (meth)acrylate, isobutyl (meth)acrylate, cyclohexyl
(meth)acrylate, 2-ethylhexyl (meth)acrylate, isodecyl
(meth)acrylate, lauryl (meth)acrylate isobornyl (meth)acrylate,
benzyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl
(meth)acrylate, methoxyethyl (meth)acrylate, ethoxyethyl
(meth)acrylate, phenoxyethyl (meth)acrylate, tetrahydrofurfuryl
(meth)acrylate, glycidyl (meth)acrylate, dimethylaminoethyl
(meth)acrylate, diethylaminoethyl (meth)acrylate,
tert-butylaminoethyl (meth)acrylate, and acetoxyethyl
(meth)acrylate, (meth)acrylamides such as, (meth)acrylamide,
N-methylol (meth)acrylamide, N-butoxyethyl (meth)acrylamide,
N,N-dimethyl (meth)acrylamide, N-isopropyl (meth)acrylamide,
N-tert-butyl (meth)acrylamide, N-tert-octyl (meth)acrylamide,
diacetone (meth)acrylamide, vinyl propionate, vinyl
2-ethylhexanoate, N-vinylamides such as: N-vinylpyrrolidione,
N-vinylcaprolactam, N-vinylformamide, and N-vinylacetamide, methyl
vinyl ether, 2-phosphate ethylene methacrylate, 2-sulphoethylene
methacrylate, ethyl vinyl ether, butyl vinyl ether, hydroxybutyl
vinyl ether, and styrene; and (b) at least one second monomer
selected from: acrylic acid, methacrylic acid, itaconic acid,
maleic acid, fumaric acid, butyl methyl maleate, vinyl sulfonic
acid 2-acrylamido-2-methylpropane sulfonic acid, styrene sulfonic
acid, vinyl phosphonic acid, vinylbenzenesulphonic acid,
.alpha.-acrylamidomethyl propanesulphonic acid, allyl phosphonic
acid, and salts of any thereof.
5. The latex composition of claim 1 wherein the at least one
ethylenically unsaturated monomer comprises: (a) a first monomer
selected from vinyl acetate; and (b) at least one second monomer
selected from: acrylic acid, methacrylic acid, maleic acid, fumaric
acid, butyl methyl maleate, vinyl sulfonic acid,
2-acrylamido-2-methylpropane sulfonic acid, styrene sulfonic acid,
vinyl phosphonic acid, vinylbenzenesulphonic acid,
.alpha.-acrylamidomethyl propanesulphonic acid, allyl phosphonic
acid, and salts of any thereof.
6. The aqueous composition of claim 1 further comprising at least
one additive selected from the group consisting of dispersants,
surfactants, rheology modifiers, defoamers, thickeners, biocides,
mildewcides, colorants, waxes, perfumes and co-solvents.
7. A process for preparing an aqueous polymer dispersion, the
process comprising the step of: contacting the compound of formula
(Ia) or formula (Ib) in an aqueous polymerization medium with at
least one ethylenically unsaturated monomers and at least one free
radical initiator; thereby allowing free-radical polymerization of
the ethylenically unsaturated monomers.
8. An aqueous composition comprising: water; optionally, a pigment;
and a film-forming latex composition with modified surface
chemistry obtained by free-radical emulsion polymerization in the
presence: of at least one ethylenically unsaturated monomer or at
least one polymer containing residual ethylenically unsaturated
bonds, of at least one free-radical polymerization initiator, and
of at least one water-soluble and/or water-dispersible polymer of
formula (I): (R.sup.11)x-Z.sup.11--C(.dbd.S)--Z.sup.12-[A]-R.sup.12
(I) wherein: Z.sup.11 represents C, N, O, S or P, Z.sup.12
represents S or P, R.sup.11 and R.sup.12, which may be identical or
different, represent: an optionally substituted alkyl, acyl, aryl,
alkene or alkyne group (i), or a saturated or unsaturated,
optionally substituted or aromatic carbon-based ring (ii), or a
saturated or unsaturated, optionally substituted heterocycle (iii),
these groups (1) rings (i) or heterocycles (iii) being optionally
substituted with substituted phenyl groups, substituted aromatic
groups or groups selected from: alkoxycarbonyl or aryloxycarbonyl
(--COOR) groups, carboxyl (--COOH) groups, acyloxy (--O.sub.2CR)
groups, carbamoyl (--CONR.sub.2) groups, cyano (--CN) groups,
alkylcarbonyl groups, alkylarylcarbonyl groups, arylcarbonyl
groups, arylalkylcarbonyl groups, phthalimido groups, maleimido
groups, succinimide groups, amidino groups, guanidimo groups,
hydroxyl (--OH) groups, amino (--NR.sub.2) groups, halogen groups,
allyl groups, epoxy groups, alkoxy (--OR) groups, S-alkyl groups,
S-aryl groups, alkali metal salts of carboxylic acids, alkali metal
salts of sulphonic acid, polyalkylene oxide (PEO or PPO) chains,
and quaternary ammonium salts, wherein R represents an alkyl or
aryl group, x corresponds to the valency of Z.sup.11, or
alternatively x is 0, in which case Z.sup.11 represents a phenyl,
alkene or alkyne radical, being optionally substituted with groups
selected from: an optionally substituted alkyl, acyl, aryl, alkene
or alkyne group, an optionally substituted, saturated, unsaturated,
or aromatic, carbon-based ring, an optionally substituted,
saturated or unsaturated heterocycle; an alkoxycarbonyl or
aryloxycarbonyl (--COOR) group, a carboxyl (COOH) group, an acyloxy
(--O.sub.2CR) group, a carbamoyl (--CONR.sub.7) group, a cyano
(--CN) group; an alkylcarbonyl group; an alkylarylcarbonyl group;
an arylcarbonyl group; an arylalkylcarbonyl group; a phthalimido
group, a maleimido group, a succinimido group, a amidino group, a
guanidimo group, a hydroxyl (--OH) group, an amino (--NR.sub.2)
group, a halogen group, an allyl group, an epoxy group, an alkoxy
(--OR) group, a S-alkyl group, a S-aryl group, an alkali metal salt
of carboxylic acid, an alkali metal salt of sulphonic acid,
polyalkylene oxide (PEO or PPO) chains, and quaternary ammonium
salts, wherein R represents an alkyl or aryl group; and A
represents a monoblock, diblock or triblock polymer comprising at
least a first block which is hydrophilic in nature and a second
block which is hydrophobic in nature.
9. The aqueous composition of claim 8 wherein the film-forming
latex composition with modified surface chemistry is obtained by
free-radical emulsion polymerization in the absence of a
surfactant.
10. The aqueous composition of claim 8 wherein the at least one
water-soluble and/or water-dispersible polymer comprising formula
(I) has a weight average molecular weight of from 5,000 to 7,000
Daltons.
11. The aqueous composition of claim 8 wherein the at least one
ethylenically unsaturated monomer comprises: (a) at least one first
monomer selected from: methyl (meth)acrylate, ethyl (meth)acrylate,
butyl (meth)acrylate, isobutyl (meth)acrylate, cyclohexyl
(meth)acrylate, 2-ethylhexyl (meth)acrylate, isodecyl
(meth)acrylate, lauryl (meth)acrylate isobornyl (meth)acrylate,
benzyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl
(meth)acrylate, methoxyethyl (meth)acrylate, ethoxyethyl
(meth)acrylate, phenoxyethyl (meth)acrylate, tetrahydrofurfuryl
(meth)acrylate, glycidyl (meth)acrylate, dimethylaminoethyl
(meth)acrylate, diethylaminoethyl (meth)acrylate,
tert-butylaminoethyl (meth)acrylate, and acetoxyethyl
(meth)acrylate, (meth)acrylamides such as, (meth)acrylamide,
N-methylol (meth)acrylamide, N-butoxyethyl (meth)acrylamide,
N,N-dimethyl (meth)acrylamide, N-isopropyl (meth)acrylamide,
N-tert-butyl (meth)acrylamide, N-tert-octyl (meth)acrylamide,
diacetone (meth)acrylamide, vinyl propionate, vinyl
2-ethylhexanoate, N-vinylamides such as: N-vinylpyrrolidione,
N-vinylcaprolactam, N-vinylformamide, and N-vinylacetamide, methyl
vinyl ether, 2-phosphate ethylene methacrylate, 2-sulphoethylene
methacrylate, ethyl vinyl ether, butyl vinyl ether, hydroxybutyl
vinyl ether, and styrene; and (b) at least one second monomer
selected from: acrylic acid, methacrylic acid, itaconic acid,
maleic acid, fumaric acid, butyl methyl maleate, vinyl sulfonic
acid 2-acrylamido-2-methylpropane sulfonic acid, styrene sulfonic
acid, vinyl phosphonic acid, vinylbenzenesulphonic acid,
.alpha.-acrylamidomethyl propanesulphonic acid, allyl phosphonic
acid, and salts of any thereof.
12. The latex composition of claim 8 wherein the at least one
ethylenically unsaturated monomer comprises: (a) a first monomer
selected from vinyl acetate; and (b) at least one second monomer
selected from: acrylic acid, methacrylic acid, maleic acid, fumaric
acid, butyl methyl maleate, vinyl sulfonic acid,
2-acrylamido-2-methylpropane sulfonic acid, styrene sulfonic acid,
vinyl phosphonic acid, vinylbenzenesulphonic acid,
.alpha.-acrylamidomethyl propanesulphonic acid, allyl phosphonic
acid, and salts of any thereof.
13. The latex composition of claim 8 wherein the at least one
ethylenically unsaturated monomer comprises: (a) a first monomer
selected from vinyl acetate; and (b) at least one second monomer
different from the first monomer.
14. The aqueous composition of claim 1 further comprising at least
one additive selected from the group consisting of dispersants,
surfactants, rheology modifiers, defoamers, thickeners, biocides,
mildewcides, colorants, waxes, perfumes and co-solvents.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application Ser. No. 62/350,374, filed Jun. 15, 2016, incorporated
herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] This invention relates to improved coatings having reduced
surfactant levels, latexes free or substantial free of surfactant,
and which have improved properties including but not limited to
water resistance and, in particular, to improved latexes prepared
by utilizing hydrophilic precursors with a Xanthate moiety (or
other chain-transfer agent or "CTA") in emulsion polymerization
without the need for emulsifying surfactants.
BACKGROUND OF THE INVENTION
[0003] Latexes are colloidal dispersions of polymer particles in
water, produced by emulsion polymerization. Latexes are used in a
broad range of applications, and offers considerable advantages for
industrial synthesis. They represent an attractive alternative to
solvent-based formulations. However, several drawbacks remain
associated with traditional latex-based coatings and processes,
mainly due to the presence of surfactants in the resulting polymer.
Surfactants typically are utilized during emulsion polymerization
(EP), which is crucial role in the formation of emulsion polymer
latexes. Typical emulsifying surfactants include anionic
surfactants, nonionic surfactants, amphoteric surfactants, and
zwitterionic surfactants. Examples of anionic emulsifying
surfactants (otherwise known as "surfactant emulsifiers") are the
alkali metal alkyl aryl sulfonates, the alkali metal alkyl sulfates
and the sulfonated alkyl esters. Other examples of well-known
emulsifiers include sodium dodecyl benzene sulfonate, sodium
dodecyl butylnaphthalene sulfonate, sodium lauryl sulfate, disodium
dodecyl diphenyl ether disulfonate, disodium n-octadecyl
sulfosuccinamate and sodium dioctyl sulfosuccinate.
[0004] However, once the latex is made, surfactants that remain are
detrimental in the final application. When exposed to water or high
humidity, surfactants negatively impact the properties of the
resulting films by migrating toward the interfaces. For example,
the effects can sometime be seen as the film becoming hazy. The
negative effects include corrosion, defects in the film such as
leaching or blistering, blooming or blushing, which reduce the
gloss or induce whitening if the surfactants clusters are swollen
with water.
SUMMARY OF INVENTION
[0005] Latexes, as described herein, are made without the use of a
surfactant, but by inducing molecular self-assembly of polymeric
emulsifier particles prepared by RAFT. In another embodiment,
latexes, as described herein, are made with little or no added
surfactant, but by inducing molecular self-assembly of polymeric
emulsifier particles prepared by RAFT.
[0006] It has been surprisingly discovered that standard latexes
can be prepared through emulsion polymerization of in particular
hydrophilic monomers can be performed directly in batch or semi
batch and conditions using water-soluble/water dispersible
macro-RAFT/MADIX agents. In such conditions, amphiphilic block
copolymers form and self-assemble into self-stabilized particles
within the course of the polymerization by polymerization-induced
self-assembly (PISA). This process solves the problems met during
the attempts to implement RAFT/MADIX in ab initio emulsion such as
loss of molecular weight control, loss of colloidal stability,
and/or formation of an intractable oily layer. The PISA process
allows the synthesis of latexes without using low molecular weight
surfactants avoiding the problems induced by these products.
[0007] It has been also demonstrated that the nano-objects obtained
during polymerization by PISA may give polymer films that resist to
water due to strong hydrogen bonding between the hydrophilic
blocks, even after 72 hours of immersion.
[0008] Low molar mass surfactants are essential to stabilize
latexes utilizing traditional processes, but they can have
detrimental effects on the latex stability when frozen or subjected
to high shear. When exposed to water or high humidity, surfactants
can also negatively impact the properties of the resulting films by
migrating toward the interfaces. They can induce corrosion, defects
in the film, reduce the gloss or induce whitening if the
surfactants clusters are swollen with water. Polymerization Induced
Self-Assembly used in the process to prepare latexes, however,
allows the preparation of latexes without molecular surfactant, by
using hydrophilic macromolecular chain transfer agents instead.
Despite the use of these hydrophilic compounds, the resulting
obtained for these latexes showed an improvement of water
resistance.
[0009] Latex is an example of an emulsion polymer which is a water
based polymer dispersion. Latex paints are used for a variety of
applications including interior and exterior, and flat, semi-gloss
and gloss applications. Latex is a stable dispersion (colloidal
emulsion) of rubber or plastic polymer microparticles in an aqueous
medium. Latexes may be natural or synthetic.
[0010] The at least one latex polymer in the aqueous coating
composition can be a pure acrylic, a styrene acrylic, a vinyl
acrylic or an acrylated ethylene vinyl acetate copolymer and is
more preferably a pure acrylic. The at least one latex polymer is
preferably derived from at least one acrylic monomer selected from
the group consisting of acrylic acid, acrylic acid esters,
methacrylic acid, and methacrylic acid esters. For example, the at
least one latex polymer can be a butyl acrylate/methyl methacrylate
copolymer or a 2-ethylhexyl acrylate/methyl methacrylate copolymer.
Typically, the at least one latex polymer is further derived from
one or more monomers selected from the group consisting of styrene,
alpha-methyl styrene, vinyl chloride, acrylonitrile,
methacrylonitrile, ureido methacrylate, vinyl acetate, vinyl esters
of branched tertiary monocarboxylic acids, itaconic acid, crotonic
acid, maleic acid, fumaric acid, ethylene, and C4-C8 conjugated
dienes.
[0011] The aqueous coating composition, in one embodiment, includes
at least one pigment. The term "pigment" as used herein includes
non-film-forming solids such as pigments, extenders, and fillers.
The at least one pigment is preferably selected from the group
consisting of TiO2 (in both anastase and rutile forms), clay
(aluminum silicate), CaCO3 (in both ground and precipitated forms),
aluminum oxide, silicon dioxide, magnesium oxide, talc (magnesium
silicate), barytes (barium sulfate), zinc oxide, zinc sulfite,
sodium oxide, potassium oxide and mixtures thereof. Suitable
mixtures include blends of metal oxides such as those sold under
the marks MINEX (oxides of silicon, aluminum, sodium and potassium
commercially available from Unimin Specialty Minerals), CELITES
(aluminum oxide and silicon dioxide commercially available from
Celite Company), ATOMITES (commercially available from English
China Clay International), and ATTAGELS (commercially available
from Engelhard). More preferably, the at least one pigment includes
TiO2, CaCO3 or clay. Generally, the mean particle sizes of the
pigments range from about 0.01 to about 50 microns. For example,
the TiO2 particles used in the aqueous coating composition
typically have a mean particle size of from about 0.15 to about
0.40 microns. The pigment can be added to the aqueous coating
composition as a powder or in slurry form. The pigment is
preferably present in the aqueous coating composition in an amount
from about 5 to about 50 percent by weight, more preferably from
about 10 to about 40 percent by weight.
[0012] The coating composition can optionally contain additives
such as one or more film-forming aids or coalescing agents.
Suitable firm-forming aids or coalescing agents include
plasticizers and drying retarders such as high boiling point polar
solvents. Other conventional coating additives such as, for
example, dispersants, additional surfactants (i.e. wetting agents),
rheology modifiers, defoamers, thickeners, additional biocides,
additional mildewcides, colorants such as colored pigments and
dyes, waxes, perfumes, co-solvents, and the like, can also be used
in accordance with the invention. For example, non-ionic and/or
ionic (e.g. anionic or cationic) surfactants can be used to produce
the polymer latex. These additives are typically present in the
aqueous coating composition in an amount from 0 to about 15% by
weight, more preferably from about 1 to about 10% by weight based
on the total weight of the coating composition.
[0013] Compositions of the present invention may have an absence of
one or more of anionic surfactant, cationic surfactant, nonionic
surfactant, zwitterionic surfactant, and/or amphoteric
surfactant.
[0014] According to one aspect, described herein are aqueous
compositions comprising:
[0015] water;
[0016] optionally, a pigment; and
[0017] a film-forming latex composition with modified surface
chemistry obtained by free-radical emulsion polymerization in the
presence:
[0018] of at least one ethylenically unsaturated monomer or at
least one polymer containing residual ethylenically unsaturated
bonds,
[0019] of at least one free-radical polymerization initiator,
and
[0020] of at least one water-soluble and/or water-dispersible
polymer of formula (Ia) or formula (Ib):
(R.sup.11)x-Z.sup.11--C(.dbd.S)--Z.sup.12-[A]-[B]-R.sup.12 (Ia),
or
(R.sup.11)x-Z.sup.11--C(.dbd.S)--Z.sup.12-[B]-R.sup.12 (Ib)
[0021] wherein:
[0022] Z.sup.11 represents C, N, O, S or P,
[0023] Z.sup.12 represents S or P,
[0024] R.sup.11 and R.sup.12, which may be identical or different,
represent: [0025] an optionally substituted alkyl, acyl, aryl,
alkene or alkyne group (i), or [0026] a saturated or unsaturated,
optionally substituted or aromatic carbon-based ring (ii), or
[0027] a saturated or unsaturated, optionally substituted
heterocycle (iii),
[0028] these groups (1) rings (i) or heterocycles (iii) being
optionally substituted with substituted phenyl groups, substituted
aromatic groups or groups selected from: [0029] alkoxycarbonyl or
aryloxycarbonyl (--COOR) groups, [0030] carboxyl (--COOH) groups,
[0031] acyloxy (--O.sub.2CR) groups, [0032] carbamoyl
(--CONR.sub.2) groups, [0033] cyano (--CN) groups, [0034]
alkylcarbonyl groups, [0035] alkylarylcarbonyl groups, [0036]
arylcarbonyl groups, [0037] arylalkylcarbonyl groups, [0038]
phthalimido groups, [0039] maleimido groups, [0040] succinimide
groups, [0041] amidino groups, [0042] guanidimo groups, [0043]
hydroxyl (--OH) groups, [0044] amino (--NR.sub.2) groups, [0045]
halogen groups, [0046] allyl groups, [0047] epoxy groups, [0048]
alkoxy (--OR) groups, [0049] S-alkyl groups, [0050] S-aryl groups,
[0051] alkali metal salts of carboxylic acids, [0052] alkali metal
salts of sulphonic acid, [0053] polyalkylene oxide (PEO or PPO)
chains, and [0054] quaternary ammonium salts, wherein R represents
an alkyl or aryl group,
[0055] x corresponds to the valency of Z.sup.11, or alternatively x
is 0, in which case Z.sup.11 represents a phenyl, alkene or alkyne
radical, being optionally substituted with groups selected
from:
[0056] an optionally substituted alkyl, acyl, aryl, alkene or
alkyne group, an optionally substituted, saturated, unsaturated, or
aromatic, carbon-based ring, an optionally substituted, saturated
or unsaturated heterocycle; an alkoxycarbonyl or aryloxycarbonyl
(--COOR) group, [0057] a carboxyl (COOH) group, [0058] an acyloxy
(--O.sub.2CR) group, [0059] a carbamoyl (--CONR.sub.2) group,
[0060] a cyano (--CN) group; [0061] an alkylcarbonyl group; [0062]
an alkylarylcarbonyl group; [0063] an arylcarbonyl group; [0064] an
arylalkylcarbonyl group; [0065] a phthalimido group, [0066] a
maleimido group, [0067] a succinimido group, [0068] a amidino
group, [0069] a guanidimo group, [0070] a hydroxyl (--OH) group,
[0071] an amino (--NR.sub.2) group, [0072] a halogen group, [0073]
an allyl group, [0074] an epoxy group, [0075] an alkoxy (--OR)
group, [0076] a S-alkyl group, [0077] a S-aryl group, [0078] an
alkali metal salt of carboxylic acid, [0079] an alkali metal salt
of sulphonic acid, [0080] polyalkylene oxide (PEO or PPO) chains,
and [0081] quaternary ammonium salts, wherein R represents an alkyl
or aryl group;
[0082] A is a monoblock, diblock or triblock polymer comprising at
least a first block which is hydrophobic in nature; and
[0083] B is a monoblock, diblock or triblock polymer comprising at
least one monomer of vinyl acetate.
[0084] In another aspect, described herein are aqueous compositions
comprising:
[0085] water;
[0086] optionally, a pigment; and
[0087] a film-forming latex composition with modified surface
chemistry obtained by free-radical emulsion polymerization in the
presence:
[0088] of at least one ethylenically unsaturated monomer or at
least one polymer containing residual ethylenically unsaturated
bonds,
[0089] of at least one free-radical polymerization initiator,
and
[0090] of at least one water-soluble and/or water-dispersible
polymer comprising formula (I):
(R.sup.11)x-Z.sup.11--C(.dbd.S)--Z.sup.12-[A]-R.sup.12 (I)
[0091] wherein:
[0092] Z.sup.11 represents C, N, O, S or P,
[0093] Z.sup.12 represents S or P,
[0094] R.sup.11 and R.sup.12, which may be identical or different,
represent: [0095] an optionally substituted alkyl, acyl, aryl,
alkene or alkyne group (i), or [0096] a saturated or unsaturated,
optionally substituted or aromatic carbon-based ring (ii), or
[0097] a saturated or unsaturated, optionally substituted
heterocycle (iii),
[0098] these groups (1) rings (i) or heterocycles (iii) being
optionally substituted with substituted phenyl groups, substituted
aromatic groups or groups selected from: [0099] alkoxycarbonyl or
aryloxycarbonyl (--COOR) groups, [0100] carboxyl (--COOH) groups,
[0101] acyloxy (--O.sub.2CR) groups, [0102] carbamoyl
(--CONR.sub.2) groups, [0103] cyano (--CN) groups, [0104]
alkylcarbonyl groups, [0105] alkylarylcarbonyl groups, [0106]
arylcarbonyl groups, [0107] arylalkylcarbonyl groups, [0108]
phthalimido groups, [0109] maleimido groups, [0110] succinimido
groups, [0111] amidine groups, [0112] guanidimo groups, [0113]
hydroxyl (--OH) groups, [0114] amino (--NR.sub.2) groups, [0115]
halogen groups, [0116] allyl groups, [0117] epoxy groups, [0118]
alkoxy (--OR) groups, [0119] S-alkyl groups, [0120] S-aryl groups,
[0121] alkali metal salts of carboxylic acids, [0122] alkali metal
salts of sulphonic acid, [0123] polyalkylene oxide (PEO or PPO)
chains, and [0124] quaternary ammonium salts, wherein R represents
an alkyl or aryl group,
[0125] x corresponds to the valency of Z.sup.11, or alternatively x
is 0, in which case Z.sup.11 represents a phenyl, alkene or alkyne
radical, being optionally substituted with groups selected
from:
[0126] an optionally substituted alkyl, acyl, aryl, alkene or
alkyne group, an optionally substituted, saturated, unsaturated, or
aromatic, carbon-based ring, an optionally substituted, saturated
or unsaturated heterocycle; an alkoxycarbonyl or aryloxycarbonyl
(--COOR) group, [0127] a carboxyl (COOH) group, [0128] an acyloxy
(--O.sub.2CR) group, [0129] a carbamoyl (--CONR.sub.2) group,
[0130] a cyano (--CN) group; [0131] an alkylcarbonyl group; [0132]
an alkylarylcarbonyl group; [0133] an arylcarbonyl group; [0134] an
arylalkylcarbonyl group; [0135] a phthalimido group, [0136] a
maleimido group, [0137] a succinimido group, [0138] a amidino
group, [0139] a guanidimo group, [0140] a hydroxyl (--OH) group,
[0141] an amino (--NR.sub.2) group, [0142] a halogen group, [0143]
an allyl group, [0144] an epoxy group, [0145] an alkoxy (--OR)
croup, [0146] a 3-alkyl group, [0147] a S-aryl group, [0148] an
alkali metal salt of carboxylic acid, [0149] an alkali metal salt
of sulphonic acid, [0150] polyalkylene oxide (PEO or PPO) chains,
and [0151] quaternary ammonium salts, wherein R represents an alkyl
or aryl group; and
[0152] A represents a monoblock, diblock or triblock polymer
comprising at least a first block which is hydrophilic in nature
and a second block which is hydrophobic in nature.
[0153] In one embodiment, the latex composition is obtained by
free-radical emulsion polymerization in the absence of a
surfactant. In another embodiment, the water-soluble and/or
water-dispersible polymer of formula (I), formula (Ia) or formula
(Ib) has a weight average molecular weight of from 5,000 to 7,000
Daltons. In another embodiment, the water-soluble and/or
water-dispersible polymer of formula (I), formula (Ia) or formula
(Ib) has a weight average molecular weight of from 1,000 to 20,000
Daltons. In another embodiment, the water-soluble and/or
water-dispersible polymer of formula (I), formula (Ia) or formula
(Ib) has a weight average molecular weight of from 1,000 to 10,000
Daltons.
[0154] In another embodiment, the at least one ethylenically
unsaturated monomer comprises:
[0155] (a) at least one first monomer selected from: methyl
(meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate,
isobutyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl
(meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate
isobornyl (meth)acrylate, benzyl (meth)acrylate, hydroxyethyl
(meth)acrylate, hydroxypropyl (meth)acrylate, methoxyethyl
(meth)acrylate, ethoxyethyl (meth)acrylate, phenoxyethyl
(meth)acrylate, tetrahydrofurfuryl (meth)acrylate, glycidyl
(meth)acrylate, dimethylaminoethyl (meth)acrylate,
diethylaminoethyl (meth)acrylate, tert-butylaminoethyl
(meth)acrylate, and acetoxyethyl (meth)acrylate, (meth)acrylamides
such as, (meth)acrylamide, N-methylol (meth)acrylamide,
N-butoxyethyl (meth)acrylamide, N,N-dimethyl (meth)acrylamide,
N-isopropyl (meth)acrylamide, N-tert-butyl (meth)acrylamide,
N-tert-octyl (meth)acrylamide, diacetone (meth)acrylamide, vinyl
propionate, vinyl 2-ethylhexanoate, N-vinylamides such as:
N-vinylpyrrolidione, N-vinylcaprolactam, N-vinylformamide, and
N-vinylacetamide, methyl vinyl ether, 2-phosphate ethylene
methacrylate, 2-sulphoethylene methacrylate, ethyl vinyl ether,
butyl vinyl ether, hydroxybutyl vinyl ether, and styrene; and
[0156] (b) at least one second monomer selected from: acrylic acid,
methacrylic acid, itaconic acid, maleic acid, fumaric acid, butyl
methyl maleate, vinyl sulfonic acid 2-acrylamido-2-methylpropane
sulfonic acid, styrene sulfonic acid, vinyl phosphonic acid,
vinylbenzenesulphonic acid, .alpha.-acrylamidomethyl
propanesulphonic acid, allyl phosphonic acid, and salts of any
thereof.
[0157] In another embodiment, the at least one ethylenically
unsaturated monomer comprises:
[0158] (a) a first monomer selected from vinyl acetate; and
[0159] (b) at least one second monomer selected from: acrylic acid,
methacrylic acid, maleic acid, fumaric acid, butyl methyl maleate,
vinyl sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid,
styrene sulfonic acid, vinyl phosphonic acid, vinylbenzenesulphonic
acid, .alpha.-acrylamidomethyl propanesulphonic acid, allyl
phosphonic acid, and salts of any thereof.
[0160] Also described herein are processes for preparing an aqueous
polymer dispersion, which in one embodiment, the process comprises
the step of contacting the compound of any of formula (I), formula
(Ia) or formula (Ib) in an aqueous polymerization medium with at
least one ethylenically unsaturated monomers and at least one free
radical initiator; thereby allowing free-radical polymerization of
the ethylenically unsaturated monomers.
[0161] These and other features and advantages of the present
invention will become more readily apparent to those skilled in the
art upon consideration of the following detailed description, which
describe both the preferred and alternative embodiments of the
present invention.
DETAILED DESCRIPTION OF INVENTION
[0162] As used herein, the term "alkyl" means a saturated straight
chain, branched chain, or cyclic hydrocarbon radical, including but
not limited to, methyl, ethyl, n-propyl, iso-propyl, n-butyl,
sec-butyl, t-butyl, pentyl, n-hexyl, and cyclohexyl.
[0163] As used herein, the term "aryl" means a monovalent
unsaturated hydrocarbon radical containing one or more six-membered
carbon rings in which the unsaturation may be represented by three
conjugated double bonds, which may be substituted with one or more
of carbons of the ring with hydroxy, alkyl, alkenyl, halo,
haloalkyl, or amino, including but not limited to, phenoxy, phenyl,
methylphenyl, dimethylphenyl, trimethylphenyl, chlorophenyl,
trichloromethylphenyl, aminophenyl, and tristyrylphenyl.
[0164] As used herein, the term "alkylene" means a divalent
saturated straight or branched chain hydrocarbon radical, such as
for example, methylene, dimethylene, trimethylene.
[0165] As used herein, the terminology "(Cr-Cs)" in reference to an
organic group, wherein r and s are each integers, indicates that
the group may contain from r carbon atoms to s carbon atoms per
group.
[0166] As used herein, the term "degree of substitution" as
employed herein is the average substitution of functional groups
per anhydro sugar unit in the polygalactomannan gum. In guar gum,
the basic unit of the polymer consists of two mannose units with a
glycosidic linkage and a galactose unit attached to the C.sub.6
hydroxyl group of one of the mannose units. On the average, each of
the anhydro sugar units contains three available hydroxyl sites. A
degree of substitution of 3 would mean that all of the available
hydroxyl sites have been esterified with functional groups.
[0167] As used herein the term "(meth)acrylate" refers collectively
and alternatively to the acrylate and methacrylate and the term
"(meth)acrylamide" refers collectively and alternatively to the
acrylamide and methacrylamide, so that, for example, "butyl
(meth)acrylate" means butyl acrylate and/or butyl methacrylate.
[0168] As used herein, "molecular weight" in reference to a polymer
or any portion thereof, means to the weight-average molecular
weight ("Mw") of the polymer or portion. Mw of a polymer is a value
measured by gel permeation chromatography (GPC) with an aqueous
eluent or an organic eluent (for example dimethylacetamide,
dimethylformamide, and the like), depending on the composition of
the polymer, light scattering (DLS or alternatively MALLS),
viscometry, or a number of other standard techniques. Mw of a
portion of a polymer is a value calculated according to known
techniques from the amounts of monomers, polymers, initiators
and/or transfer agents used to make the portion.
[0169] In one embodiment, the copolymers for use in the present
invention exhibit a weight average molecular weight, as determined
by gel permeation chromatography (GPC) and light scattering of a
solution of the polymer in tetrahydrofuran and compared to a
polystyrene standard, of greater than or equal to 30,000 grams per
mole ("g/mole"). HASE thickeners may not fully dissolve in THF but
after hydrolysis they can dissolve in water and measurement can be
run in a water gel permeation chromatography (GPC). Reference:
Macromolecules 2000, 33, 2480. For example in a range of 30,000 to
2,000,000 g/mole.
[0170] As used herein, each of the terms "monomer", "polymer",
"homopolymer", "copolymer", "linear polymer", "branched polymer",
"star polymer", "comb polymer", "random copolymer", alternating
copolymer", "block copolymer", "graft copolymer", has the meaning
ascribed to it in Glossary of basic terms in polymer science (IUPAC
Recommendations 1996), Pure Appl. Chem., Vol. 68, No. 12, pp.
2287-2311, 1996.
[0171] As used herein, the indication that a radical may be
"optionally substituted" or "optionally further substituted" means,
in general, unless further limited, either explicitly or by the
context of such reference, such radical may be substituted with one
or more inorganic or organic substituent groups, for example,
alkyl, alkenyl, aryl, arylalkyl, alkaryl, a hetero atom, or
heterocyclyl, or with one or more functional groups capable of
coordinating to metal ions, such as hydroxyl, carbonyl, carboxyl,
amino, imino, amido, phosphonic acid, sulphonic acid, or arsenate,
or inorganic and organic esters thereof, such as, for example,
sulphate or phosphate, or salts thereof.
[0172] As used herein, the term "water-soluble copolymer" means a
copolymer which, when it is brought into contact with water,
spontaneously forms a solution which tends to homogenize. If the
mixture is left for several days with gentle agitation, any sample
taken from any place in the volume occupied by the sample gives the
same concentration value as the mean concentration value. Included
in this definition are not only completely soluble copolymers, but
also copolymers which form a homogeneous solution having a slight
turbidity due to local aggregation of the copolymer.
[0173] As used herein, the term "amphiphilic copolymer" means a
copolymer obtained by polymerization of hydrophilic monomers and
hydrophobic monomers; this copolymer comprises hydrophobic segments
and hydrophilic segments and, as a result, exhibits different
regions of solubility in water.
[0174] As used herein, "parts by weight" or "pbw" in reference to a
named compound refers to the amount of the named compound,
exclusive, for example, of any associated solvent. In some
instances, the trade name of the commercial source of the compound
is also given, typically in parentheses. For example, a reference
to "10 pbw cocoamidopropylbetaine ("CAPB", as MIRATAINE BET C-30)"
means 10 pbw of the actual betaine compound, added in the form of a
commercially available aqueous solution of the betaine compound
having the trade name "MIRATAINE BET C-30", and exclusive of the
water contained in the aqueous solution.
[0175] As used herein, an indication that a composition is
"substantially free" of a specific material, means the composition
contains no more than an insubstantial amount of that material, and
an "insubstantial amount" means an amount that does not measurably
affect the desired properties of the composition.
[0176] As used herein, the term "surfactant" means a compound that
reduces surface tension when dissolved in water.
[0177] As used herein, suitable polymerizable functional groups
include, for example, acrylo, methacrylo, acrylamido,
methacrylamido, diallylamino, allyl ether, vinyl ether,
.alpha.-alkenyl, maleimido, styrenyl, and .alpha.-alkyl styrenyl
groups.
[0178] Latex (emulsion polymers) are used commonly and widely in
paints and coatings, adhesives, sealants and elastomeric
applications. Typical preparation for the industrial production of
latex polymers involves the use of monomers from styrene, butyl
acrylate, and ethyl hexyl acrylate to vinyl acetate to gaseous
monomers such as ethylene, plus typical initiators such as ammonium
persulfate etc. and surfactants to stabilize the latex particles
ranging from 40 to 500 nm (typically 80-250 nm).
[0179] The amount of surfactant used to make the latex can range
between 1-3% based on the total amount of monomers. Surfactants are
used to not only control the particle size but also to provide
shear stability and therefore play a crucial in preparation of
latexes and long term shelf stability of the latex.
[0180] The advantages of using surfactants of different types for
the above benefits are then outweighed by the need to minimize the
surfactant levels to obtain films of latex that can give excellent
water resistance together with adhesion to substrates. The
importance of reducing surfactants therefore becomes critical and
more critical in paint films (with low or high PVC) as the presence
of surfactants tends to diminish the aesthetic appearance of the
paint film (blistering, leaching, craters etc.).
[0181] To improve the water resistance of latex films and that of
paint films in particular especially for latex polymers based on
co-polymers of vinyl acetate, or co-polymers of styrene acrylates,
the usage of surfactant has been minimized or attempts have been
made using polymerizable surfactants. In both cases results have
not been satisfactory in obtaining good water resistance or other
performance properties.
[0182] In one embodiment, the use of hydrophilic precursors with a
xanthate moiety (otherwise, herein referred to as "Macro CTA") in
emulsion polymerization of at least one monomer have been prepared
to yield stable latexes with particle size ranging from 80-200 nm.
In one embodiment, the films of the polymers prepared using Macro
CTA show surprisingly good water resistance as measured through a
variety of test methods for water resistance namely the water
droplet, water immersion and water vapor. In another embodiment,
the use of hydrophilic precursors with a xanthate moiety in
emulsion polymerization of a vinyl acetate monomer with other
co-monomers yielded stable latexes with particle size ranging from
80-200 nm and the films of the polymers are showing surprisingly
exceptional water resistance as measured through a variety of test
methods for water resistance namely the water droplet, water
immersion and water vapor.
[0183] In one embodiment, use of hydrophilic precursors with a
xanthate moiety in emulsion polymerization of a styrene monomer
with other co-monomers yielded stable latexes. in particular vinyl
acetate with other co-monomers and also of styrene with other
co-monomers The films of the above prepared latex with Macro CTA
for example were tested by the water immersion test by soaking the
film of the latex in water for up to 8 days and monitoring for
blushing (whiteness) or any other film defects, and by the water
vapor method for an hour against film of commercial latexes and
latexes produced using standard surfactants.
[0184] In one embodiment, films of latex based on commercial latex
and those with surfactants prepared in the laboratory blush (the
degree of whiteness) after 24 hours and the blush of the film
becomes progressively deeper over time, while the film of latex
based on co-polymers of vinyl acetate or styrene acrylic show no
tendency toward whiteness even after 8 days of allowing the films
to soak in water.
[0185] Latexes prepared using Macro CTA and based on co-polymers of
vinyl acetate and of co-monomer of styrene (as compared to latexes
based on surfactants) have shown enhanced shear stability, freeze
thaw and electrolyte stability and films of the latex show enhanced
adhesion to metallic substrate.
[0186] In some embodiments, the latex prepared using Macro CTA
(containing Xanthate moiety) can easily be scaled for commercial
purposes. The preparation of the seed of above latex polymers
(vinyl acetate co-polymers and or of styrene copolymers), which is
part of the preparation in making latexes of high solids are also
claimed as key finding of this disclosure.
[0187] Macro CTA can also be utilized with the use of specialty
monomers that are available will allow for tailoring of latexes for
various performances and multifunctional performance and thereby
extending the application beyond just paints and coating
applications, which include but are not limited to coatings,
adhesives, sealants, elastomeric applications, and the like.
[0188] The latex of the present invention comprises, in dispersion,
a water-insoluble polymer obtained from monomers comprising
ethylenic unsaturation. The monomers as mentioned herein can be
used as ethylenically unsaturated monomers involved in the
production of the latex. Latexes with modified surface properties,
which can be obtained using a method which comprises addition of a
water-soluble amphiphilic copolymer to an aqueous dispersion of a
water-insoluble polymer or copolymer obtained from monomers with
ethylenic unsaturation.
[0189] In one embodiment, the latexes can be used as binding agents
in various applications in the fields of paint, papermaking
coating, coatings and construction materials.
[0190] In one embodiment, a non-surfactant copolymer can be
obtained through the choice of monomers, including but not limited
to, for example, a Styrene/BA copolymer is non-surfactant. It is
also possible to obtain a non-surfactant block copolymer by
increasing the molecular mass or by decreasing the fraction of
hydrophobic monomers in the copolymer.
[0191] In general, the water-soluble amphiphilic block copolymers
described above can be obtained by any polymerization process
referred to as "living" or "controlled", such as, for example:
[0192] free-radical polymerization controlled by xanthates,
according to the teaching of application WO 98/58974,
[0193] free-radical polymerization controlled by dithioesters,
according to the teaching of application WO 97/01478,
[0194] polymerization using nitroxide precursors, according to the
teaching of application WO 99/03894,
[0195] free-radical polymerization controlled by dithiocarbamates,
according to the teaching of application WO 99/31144, and/or
[0196] atom transfer free-radical polymerization (ATRP), according
to the teaching of application WO 96/30421.
[0197] Macro CTA
[0198] A monoblock, diblock or triblock polymer corresponds to the
following formula (I):
(R.sup.11)x-Z.sup.11--C(.dbd.S)--Z.sup.12-[A]-R.sup.12 (I)
[0199] in which formula:
[0200] Z.sup.11 represents C, N, O, S or P,
[0201] Z.sup.12 represents S or P,
[0202] R.sup.11 and R.sup.12, which may be identical or different,
represent: [0203] an optionally substituted alkyl, acyl, aryl,
alkene or alkyne group (i), or [0204] a saturated or unsaturated,
optionally substituted or aromatic carbon-based ring (ii), or
[0205] a saturated or unsaturated, optionally substituted
heterocycle (iii), these groups and rings (i), (ii) and (iii)
possibly being substituted with substituted phenyl groups,
substituted aromatic groups or groups: alkoxycarbonyl or
aryloxycarbonyl (--COOR), carboxyl (--COOH), acyloxy (--O.sub.2CR),
carbamoyl (--CONR.sub.2), cyano (--CN), alkylcarbonyl,
alkylarylcarbonyl, arylcarbonyl, arylalkylcarbonyl, phthalimido,
maleimido, succinimido, amidino, guanidimo, hydroxyl (--OH), amino
(--NR.sub.2), halogen, allyl, epoxy, alkoxy (--OR), S-alkyl,
S-aryl, groups of hydrophilic or ionic nature such as the alkali
metal salts of carboxylic acids, the alkali metal salts of
sulphonic acid, polyalkylene oxide (PEO or PPO) chains and cationic
substituents (quaternary ammonium salts), [0206] R representing an
alkyl or aryl group,
[0207] x corresponds to the valency of Z.sup.11, or
alternatively
[0208] x is 0, in which case Z.sup.11 represents a phenyl, alkene
or alkyne radical, optionally substituted with an optionally
substituted alkyl; acyl; aryl; alkene or alkyne group; an
optionally substituted, saturated, unsaturated, or aromatic,
carbon-based ring; an optionally substituted, saturated or
unsaturated heterocycle; alkoxycarbonyl or aryloxycarbonyl
(--COOR); carboxyl (COOH); acyloxy (--O.sub.2CR), carbamoyl
(--CONR.sub.2); cyano (--CN); alkylcarbonyl, alkylarylcarbonyl;
arylcarbonyl; arylalkylcarbonyl; phthalimido; maleimido;
succinimido; amidino; guanidimo; hydroxyl (--OH); amino
(--NR.sub.2); halogen; allyl; epoxy; alkoxy (--OR), S-alkyl; S-aryl
groups; groups of hydrophilic or ionic nature such as the alkali
metal salts of carboxylic acids, the alkali metal salts of
sulphonic acid, polyalkylene oxide (PEO or PPO) chains and cationic
substituents (quaternary ammonium salts);
[0209] -[A]- represents a monoblock, diblock or triblock
polymer.
[0210] According to one advantageous variant of the invention, the
compound of formula (I), formula (Ia) or formula (Ib) is such that
Z.sup.11 is an oxygen atom and Z.sup.12 is a sulphur atom. These
compounds are thus functionalized at the end of the chain with
xanthates.
[0211] In one embodiment, -[A]- corresponds more particularly to at
least one of the three formulae below:
##STR00001##
[0212] in which formulae: [0213] Va, V'a, Vb, V'b, Vc and V'c,
which may be identical or different, represent: H, an alkyl group
or a halogen, [0214] Xa, X'a, Xb, X'b, Xc and X'c, which may be
identical or different, represent H, a halogen or a group R, OR,
OCOR, NHCOH, OH, NH2, NHR, N(R).sub.2, (R).sub.2N.sup.+O.sup.-,
NHCOR, CO.sub.2H, CO.sub.2R, CN, CONH.sub.2, CONHR or CONR.sub.2,
in which R, which may be identical or different, are chosen from
alkyl, aryl, aralkyl, alkaryl, alkene and organosilyl groups,
optionally perfluorinated and optionally substituted with one or
more carboxyl, epoxy, hydroxyl, alkoxy, amino, halogen or sulphonic
groups, [0215] l, m and n, which may be identical or different, are
greater than or equal to 1 [0216] x, y and z, which may be
identical or different, are equal to 0 or 1.
[0217] More particularly, [A] is obtained by using at least one
ethylenically unsaturated monomer chosen from hydrophilic
monomers.
[0218] Examples of such monomers that may especially be mentioned
include [0219] ethylenically unsaturated monocarboxylic and
dicarboxylic acids, for instance acrylic acid, methacrylic acid,
itaconic acid, maleic acid or fumaric acid, [0220] monoalkyl esters
of dicarboxylic acids of the type mentioned with alkanols
preferably containing 1 to 4 carbon atoms, and N-substituted
derivatives thereof, such as, 2-hydroxyethyl acrylate or
methacrylate, [0221] unsaturated carboxylic acid amides, for
instance acrylamide or methacrylamide, [0222] ethylenic monomers
comprising a sulphonic acid group and ammonium or alkali metal
salts thereof, for example vinylsulphonic acid,
vinylbenzenesulphonic acid, .alpha.-acrylamidomethyl
propanesulphonic acid or 2-sulphoethylene methacrylate.
[0223] It is possible to incorporate into the polymer composition a
proportion of hydrophobic monomers, provided that the
solubility/dispersity conditions and the conditions of
non-formation of gelled or non-gelled micelles, mentioned
previously, remain valid.
[0224] Illustrations of hydrophobic monomers that may especially be
mentioned include styrene or its derivatives, butadiene,
chloroprene, (meth)acrylic esters, vinyl esters and vinyl
nitriles.
[0225] The term "(meth)acrylic esters" denotes esters of acrylic
acid and of methacrylic acid with hydrogenated or fluorinated
C.sub.1-C.sub.12 and preferably C.sub.1-C.sub.8 alcohols. Among the
compounds of this type that may be mentioned are: methyl acrylate,
ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl
acrylate, 2-ethylhexyl acrylate, t-butyl acrylate, methyl
methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl
methacrylate.
[0226] The vinyl nitriles more particularly include those
containing from 3 to 12 carbon atoms, such as, in particular,
acrylonitrile and methacrylonitrile.
[0227] It should be noted that the styrene may be totally or
partially replaced with derivatives such as .alpha.-methylstyrene
or vinyltoluene.
[0228] The other ethylenically unsaturated monomers that may be
used, alone or as mixtures, or that are copolymerizable with the
above monomers are especially: [0229] vinyl esters of a carboxylic
acid, for instance vinyl acetate, vinyl versatate or vinyl
propionate, [0230] vinyl halides, [0231] vinylamine amides,
especially vinylformamide or vinylacetamide, [0232] ethylenically
unsaturated monomers comprising a secondary, tertiary or quaternary
amino group, or a heterocyclic group containing nitrogen, such as,
for example, vinylpyridines, vinylimidazole, aminoalkyl
(meth)acrylates and aminoalkyl(meth)acrylamides, for instance
dimethylaminoethyl acrylate or methacrylate,
di-tert-butylaminoethyl acrylate or methacrylate,
dimethylaminomethylacrylamide or dimethylaminomethylmethacrylamide,
or ethylene ureido functionality attached to derivatives of
ethylene oxide or propylene oxide of allyl glycidal ether or
methacrylate derivatives such as N(2-methacryloyloxyethyl)ethylene
urea. It is likewise possible to use zwitterionic monomers such as,
for example, sulphopropyl (dimethyl)aminopropyl acrylate, [0233]
ethylenic monomers comprising a phosphate acid group and ammonium
or alkali metal salts thereof, for example vinylphosphonic acid or
2-phosphate ethylene methacrylate.
[0234] According to one particularly advantageous embodiment, the
polymer A is a monoblock or a diblock polymer.
[0235] In one embodiment, polymer A has a number-average molar mass
of less than 1000 and preferably less than 20000. In another
embodiment, polymer A has a weight average molecular weight of less
than 1000 and preferably less than 20000. These molar masses are
measured by steric exclusion chromatography, using polyethylene
glycol as standard.
[0236] According to a second embodiment of the invention, the
monoblock, diblock or triblock polymer used is a polymer
corresponding to the following formulae:
##STR00002##
[0237] in which formulae: [0238] X represents an atom chosen from
N, C, P and Si, [0239] R.sup.22 represents: [0240] an optionally
substituted alkyl, acyl, aryl, alkene or alkyne group (i), or
[0241] a saturated or unsaturated, optionally substituted or
aromatic carbon-based ring (ii), or [0242] a saturated or
unsaturated, optionally [0243] substituted or aromatic heterocycle
(iii), these groups and rings (i), (ii) and (iii) possibly being
substituted with substituted phenyl groups, substituted aromatic
groups or groups: [0244] alkoxycarbonyl or aryloxycarbonyl
(--COOR), carboxyl (--COOH), acyloxy (--O.sub.2CR), carbamoyl
(--CONR.sub.2), cyano (--CN), alkylcarbonyl, alkylarylcarbonyl,
arylcarbonyl, arylalkylcarbonyl, phthalimido, maleimido,
succinimido, amidino, guanidimo, hydroxyl (--OH), amino
(--NR.sub.2), halogen, allyl, epoxy, alkoxy (--OR), S-alkyl,
S-aryl, organosilyl, groups of hydrophilic or ionic nature such as
the alkali metal salts of carboxylic acids, the alkali metal salts
of sulphonic acid, polyalkylene oxide (PEO or PPO) chains and
cationic substituents (quaternary ammonium salts), [0245] R
representing an alkyl or aryl group, [0246] Z, R.sup.21i and
R.sup.23, which may be identical or different, are chosen from:
[0247] a hydrogen atom, [0248] an optionally substituted alkyl,
acyl, aryl, alkene or alkyne group, [0249] a saturated or
unsaturated, optionally substituted or aromatic carbon-based ring,
[0250] a saturated or unsaturated, optionally substituted
heterocycle, [0251] alkoxycarbonyl or aryloxycarbonyl (--COOR),
carboxyl (--COOH), acyloxy (--O.sub.2CR), carbamoyl (--CONR.sub.2),
cyano (--CN), alkylcarbonyl, alkylarylcarbonyl, arylcarbonyl,
arylalkylcarbonyl, phthalimido, maleimido, succinimide, amidino,
guanidimo, hydroxyl (--OH), amino (--NR2), halogen, allyl, epoxy,
alkoxy (--OR), S-alkyl, S-aryl and organosilyl groups, R
representing an alkyl or aryl group, [0252] groups of hydrophilic
or ionic nature such as the alkali metal salts of carboxylic acids,
the alkali metal salts of sulphonic acid, polyalkylene oxide (PEO
or PPO) chains and cationic substituents (quaternary ammonium
salts), [0253] n>0, [0254] i ranges from 1 to n, [0255] p is
equal to 0, 1 or 2 depending on the valency of X, and also [0256]
if X=C, then Z is not an S-alkyl or S-aryl group, [0257] the group
R.sup.11, where i=n, is not an S-alkyl or S-aryl group, [0258] A
represents a monoblock, diblock or triblock polymer as defined
herein.
[0259] In order to obtain water-soluble amphiphilic copolymers
comprising hydrophilic and hydrophobic blocks, this process
consists in forming a first block according to the following
steps:
[0260] (1) bringing into contact: [0261] at least one ethylenically
unsaturated monomer, [0262] at least one source of free radicals,
and [0263] at least one compound of formula (I), formula (Ia) or
formula (Ib) as described herein;
[0264] (2) forming a second block by repeating step 1 using:
monomers which are different in nature, and in place of the
precursor compound of formula (I), formula (Ia) or formula (Ib),
the polymer derived from step 1; and
[0265] (3) Optionally hydrolyzing, at least partially, the
copolymer obtained.
[0266] During step 1, a first block of the polymer is synthesized
which is mainly hydrophilic or hydrophobic in nature depending on
the nature and the amount of the monomers used. During step 2, the
other block of the polymer is synthesized.
[0267] The ethylenically unsaturated monomers will be chosen from
the hydrophilic, hydrophobic and hydrolyzable monomers defined
herein, in proportions suitable for obtaining a block copolymer in
which the blocks exhibit the characteristics defined above.
[0268] According to this process, if all the successive
polymerizations are carried out in the same reactor, it is
generally preferable for all the monomers used in a step to be
consumed before the polymerization of the subsequent step begins,
therefore before the new monomers are introduced. However, it may
so happen that the hydrophobic or hydrophilic monomers of the
preceding step are still present in the reactor during the
polymerization of the subsequent block. In this case, these
monomers generally represent no more than 5 mol % of all the
monomers and they participate in the polymerization by contributing
to the introduction of the hydrophobic or hydrophilic units into
the subsequent block.
[0269] A water-soluble amphiphilic copolymer comprising blocks
which are hydrophilic in nature and which are hydrophobic in nature
can be obtained from a single type of hydrophobic hydrolyzable
monomer. In this case, step 2 is no longer necessary, but partial
hydrolysis of the polymer is then essential.
[0270] Using the same process, it is possible to obtain a copolymer
comprising n blocks by repeating the preceding steps 1 and 2, but
replacing the compound of formula (I), formula (Ia) or formula (Ib)
with the copolymer comprising n-1 blocks.
[0271] In one embodiment, the copolymers obtained by the processes
described above generally exhibit a polydispersity index of at most
2, typically of at most 1.5. It may be desired to mix with the
latex blocks whose polydispersity is controlled. In this case, it
is possible to mix, in precise proportions, several water-soluble
amphiphilic copolymers comprising a block which is hydrophilic in
nature and a block which is hydrophobic in nature, each having a
clearly defined molecular mass.
[0272] In one embodiment, described herein are methods of preparing
an aqueous coating composition by mixing together at least one
latex polymer derived from at least one monomer and at least one
pigment. Preferably, the latex polymer is in the form of latex
polymer dispersion. The additives discussed above can be added in
any suitable order to the latex polymer, the pigment, or
combinations thereof, to provide these additives in the aqueous
coating composition. In the case of paint formulations, the aqueous
coating composition preferably has a pH of from 7 to 10.
[0273] In formulating latexes and latex paints/coatings, physical
properties that may be considered include, but are not limited to,
viscosity versus shear rate, ease of application to surface,
spreadability, and shear thinning.
[0274] When hydrolyzable hydrophobic monomers are used, the
hydrolysis may be carried out using a base or an acid. The base can
be chosen from alkali metal or alkaline earth metal hydroxides,
such as sodium hydroxide or potassium hydroxide, alkali metal
alkoxides, such as sodium methoxide, sodium ethoxide, potassium
methoxide, potassium ethoxide or potassium t-butoxide, ammonia and
amines, such as triethylamines. The acids can be chosen from
sulfuric acid, hydrochloric acid and para-toluenesulfonic acid. Use
may also be made of an ion-exchange resin or an ion-exchange
membrane of the cationic or anionic type. The hydrolysis is
generally carried out at a temperature of between 5 and 100.degree.
C., preferably between 15 and 90.degree. C. Preferably, after
hydrolysis, the block copolymer is washed, for example by dialysis
against water or using a solvent such as alcohol. It may also be
precipitated by lowering the pH below 4.5.
[0275] The hydrolysis may be carried out on a single-block polymer,
which will subsequently be associated with other blocks, or on the
final block polymer.
[0276] The latex of the present invention comprises, in dispersion,
a water-insoluble polymer obtained from monomers comprising
ethylenic unsaturation. All the monomers which had been mentioned
in the context of the definition of the water-soluble amphiphilic
copolymer can be used as monomers comprising ethylenic
unsaturations involved in the production of the latex. Reference
may therefore be made to this part of the description for choosing
a useful monomer comprising ethylenic unsaturation.
[0277] The monomers typically employed in emulsion polymerization
to make latex for latex paint include, but are not limited to such
monomers as methyl acrylate, ethyl acrylate, methyl methacrylate,
butyl acrylate, 2-ethyl hexyl acrylate, other acrylates,
methacrylates and their blends, acrylic acid, methacrylic acid,
styrene, vinyl toluene, vinyl acetate, vinyl esters of higher
carboxylic acids than acetic acid, e.g. vinyl versatate,
acrylonitrile, acrylamide, butadiene, ethylene, vinyl chloride and
the like, and mixtures thereof. This is further discussed below in
the section entitled "Latex Monomers".
[0278] The latex monomers fed to a reactor to prepare the polymer
latex binder preferably include at least one acrylic monomer
selected from the group consisting of acrylic acid, acrylic acid
esters, methacrylic acid, and methacrylic acid esters. In addition,
the monomers can include styrene, vinyl acetate, or ethylene. The
monomers can also include one or more monomers selected from the
group consisting of styrene, (alpha)-methyl styrene, vinyl
chloride, acrylonitrile, methacrylonitrile, ureido methacrylate,
vinyl acetate, vinyl esters of branched tertiary monocarboxylic
acids (e.g. vinyl esters commercially available under the mark
VEOVA from Shell Chemical Company or sold as EXXAR neo vinyl esters
by ExxonMobil Chemical Company), itaconic acid, crotonic acid,
maleic acid, fumaric acid, and ethylene. It is also possible to
include C4-C8 conjugated dienes such as 1,3-butadiene, isoprene or
chloroprene. Commonly used monomers in making acrylic paints are
butyl acrylate, methyl methacrylate, ethyl acrylate and the like.
Preferably, the monomers include one or more monomers selected from
the group consisting of n-butyl acrylate, methyl methacrylate,
styrene and 2-ethylhexyl acrylate.
[0279] The latex polymer is typically selected from the group
consisting of pure acrylics (comprising acrylic acid, methacrylic
acid, an acrylate ester, and/or a methacrylate ester as the main
monomers); styrene acrylics (comprising styrene and acrylic acid,
methacrylic acid, an acrylate ester, and/or a methacrylate ester as
the main monomers); vinyl acrylics (comprising vinyl acetate and
acrylic acid, methacrylic acid, an acrylate ester, and/or a
methacrylate ester as the main monomers); and acrylated ethylene
vinyl acetate copolymers (comprising ethylene, vinyl acetate and
acrylic acid, methacrylic acid, an acrylate ester, and/or a
methacrylate ester as the main monomers). The monomers can also
include other main monomers such as acrylamide and acrylonitrile,
and one or more functional monomers such as itaconic acid and
ureido methacrylate, as would be readily understood by hose skilled
in the art. In a particularly preferred embodiment, the latex
polymer is a pure acrylic such as a butyl acrylate/methyl
methacrylate copolymer derived from monomers including butyl
acrylate and methyl methacrylate.
[0280] In typical acrylic paint compositions the polymer is
comprised of one or more esters of acrylic or methacrylic acid,
typically a mixture, e.g. about 50/50 by weight, of a high Tg
monomer (e.g. methyl methacrylate) and a low Tg monomer (e.g. butyl
acrylate), with small proportions, e.g. about 0.5% to about 2% by
weight, of acrylic or methacrylic acid. The vinyl-acrylic paints
usually include vinyl acetate and butyl acrylate and/or 2-ethyl
hexyl acrylate and/or vinyl versatate. In vinyl-acrylic paint
compositions, at least 50% of the polymer formed is comprised of
vinyl acetate, with the remainder being selected from the esters of
acrylic or methacrylic acid. The styrene/acrylic polymers are
typically similar to the acrylic polymers, with styrene substituted
for all or a portion of the methacrylate monomer thereof.
[0281] The latex polymer dispersion preferably includes from about
30 to about 75% solids and a mean latex particle size of from about
70 to about 650 nm. The latex polymer is preferably present in the
aqueous coating composition in an amount from about 5 to about 60
percent by weight, and more preferably from about 8 to about 40
percent by weight (i.e. the weight percentage of the dry latex
polymer based on the total weight of the coating composition).
[0282] The aqueous coating composition is a stable fluid that can
be applied to a wide variety of materials such as, for example,
paper, wood, concrete, metal, glass, ceramics, plastics, plaster,
and roofing substrates such as asphaltic coatings, roofing felts,
foamed polyurethane insulation; or to previously painted, primed,
undercoated, worn, or weathered substrates. The aqueous coating
composition of the invention can be applied to the materials by a
variety of techniques well known in the art such as, for example,
brush, rollers, mops, air-assisted or airless spray, electrostatic
spray, and the like.
[0283] Latex paint formulations typically comprise additives, e.g.,
at least one pigment. In a preferred embodiment of the invention
the latex paint formulation includes at least one pigment selected
from the group consisting of TiO2, CaCO3, clay, aluminum oxide,
silicon dioxide, magnesium oxide, sodium oxide, potassium oxide,
talc, barytes, zinc oxide, zinc sulfite and mixtures thereof. More
preferably the at least one pigment includes TiO2, calcium
carbonate or clay.
[0284] In addition to the above components, the aqueous coating
composition can include one or more additives selected from the
group consisting of dispersants, surfactants, rheology modifiers,
defoamers, thickeners, biocides, mildewcides, colorants, waxes,
perfumes and co-solvents.
[0285] In one embodiment, the composition of the present invention
(for example paints or stains) comprises the selected polymer and a
liquid carrier.
[0286] In one embodiment, the liquid carrier is an aqueous carrier
comprising water and the treatment solution is in the form of a
solution, emulsion, or dispersion of the material and additives. In
one embodiment, the liquid carrier comprises water and a water
miscible organic liquid. Suitable water miscible organic liquids
include saturated or unsaturated monohydric alcohols and polyhydric
alcohols, such as, for example, methanol, ethanol, isopropanol,
cetyl alcohol, benzyl alcohol, oleyl alcohol, 2-butoxyethanol, and
ethylene glycol, as well as alkylether diols, such as, for example,
ethylene glycol monoethyl ether, propylene glycol monoethyl ether
and diethylene glycol monomethyl ether.
[0287] As used herein, terms "aqueous medium" and "aqueous media"
are used herein to refer to any liquid medium of which water is a
major component. Thus, the term includes water per se as well as
aqueous solutions and dispersions.
[0288] Monomers:
[0289] The monomers can be copolymerized in such proportions, and
the resulting emulsion polymers can be physically blended, to give
products with the desired balance of properties for specific
applications. For example, for analogous polymers of a given
molecular weight, increasing the amount of first monomer tends to
increase the yield strength exhibited by the polymer, increasing
the relative amount of second monomer tends to increase the
viscosity of the polymer. One or more fourth monomers may be added
to adjust the properties of the polymer.
[0290] Ethylenically Unsaturated Monomers
[0291] In one embodiment, the reactive group of the additional
associative monomer is an ethylenically unsaturated group and the
monomer is an ethylenically unsaturated monomer comprising at least
one site of ethylenic unsaturation, more typically, an .alpha.-,
.beta.-unsaturated carbonyl moiety, and at least one group
according to structure (D.XXI) per molecule and copolymerizable
with the acidic monomer and the non-ionic monomer.
[0292] In one embodiment, the optional additional associative
monomer comprises one or more compounds according to structure
(D.XXIII):
R.sup.24--R.sup.23--R.sup.22--R.sup.21 (D.XXIII)
wherein:
[0293] R.sup.21, R.sup.22, and R.sup.23 are each as described
above, and
[0294] R.sup.24 is a moiety having a site of ethylenic
unsaturation. Thus the resulting hydrophobic monomeric unit has the
structure (D.XXIV):
##STR00003##
[0295] In one embodiment, the compound according to structure
(D.XXI) is an .alpha.-, .beta.-unsaturated carbonyl compound. In
one embodiment, R.sup.23 is according to structure (D.X).
[0296] In one embodiment, the additional associative monomer
comprises one or more compounds according to structure (D.XXV):
##STR00004##
[0297] wherein
R.sup.21 is linear or branched (C.sub.5-C.sub.50)alkyl,
hydroxyalkyl, alkoxyalkyl, aryl, or arylalkyl, R.sup.25 is methyl
or ethyl, and p and q are independently integers of from 2 to 5,
more typically 2 or 3, each r is independently an integer of from 1
to about 80, more typically from 1 to about 50, each s is
independently an integer of from 0 to about 80, more typically from
0 to about 50, t is an integer of from 1 to about 50, provided that
the product obtained by multiplying the integer t times the sum of
r+s is from 2 to about 100; or p, q, r, s, and t are each as
otherwise described above.
[0298] In one embodiment, the additional associative monomer
comprises one or more compounds according to structure (D.XXV)
wherein R.sup.21 is linear (C.sub.16-C.sub.22)alkyl.
[0299] In one embodiment, the optional additional associative
monomer comprises one or more compounds according to structure
(D.XXV) wherein R.sup.21 is a branched (C.sub.5-C.sub.50)alkyl
group, more typically a branched (C.sub.5-C.sub.50)alkyl group
according to structure (D.VIII). For example R.sup.21 may have the
structure D.XXVI
##STR00005##
wherein m and n each, independently, are positive integers from 1
to 39 and m+n represents an integer from 4 to 40, as disclosed by
US Patent Application Publication 2006/02700563 A1 to Yang et al,
incorporated herein by reference.
[0300] In one embodiment, the optional additional associative
monomer comprises one or more compounds according to structure
(D.XXV) wherein p=2, s=0, and t=1.
[0301] In one embodiment, the optional additional associative
monomer comprises one or more compounds according to structure
(D.XXV) wherein R.sup.21 is linear (C.sub.16-C.sub.22)alkyl,
R.sup.25 is methyl or ethyl, p=2, s=0, and t=1.
[0302] Suitable ethylenically unsaturated optional additional
associative monomers include:
[0303] alkyl-polyether (meth)acrylates that comprise at least one
linear or branched (C.sub.5-C.sub.40)alkyl-polyether group per
molecule, such as hexyl polyalkoxylated (meth)acrylates, tridecyl
polyalkoxylated (meth)acrylates, myristyl polyalkoxylated
(meth)acrylates, cetyl polyalkoxylated (meth)acrylates, stearyl
polyalkoxylated (methyl)acrylates, eicosyl polyalkoxylated
(meth)acrylates, behenyl polyalkoxylated (meth)acrylates, melissyl
polyalkoxylated (meth)acrylates, tristyrylphenoxyl polyalkoxylated
(meth)acrylates, and mixtures thereof,
[0304] alkyl-polyether (meth)acrylamides that comprise at least one
(C.sub.5-C.sub.40)alkyl-polyether substituent group per molecule,
such as hexyl polyalkoxylated (meth)acrylamides, tridecyl
polyalkoxylated (meth) acrylamides, myristyl polyalkoxylated (meth)
acrylamides, cetyl polyalkoxylated (meth)acrylamides, stearyl
polyalkoxylated (methyl) acrylamides, eicosyl polyalkoxylated
(meth) acrylamides, behenyl polyalkoxylated (meth) acrylamides,
melissyl polyalkoxylated (meth) acrylamides and mixtures
thereof,
[0305] alkyl-polyether vinyl esters, alkyl-polyether vinyl ethers,
or alkyl-polyether vinyl amides that comprise at least one
(C.sub.5-C.sub.40)alkyl-polyether substituent group per molecule
such as vinyl stearate polyalkoxylate, myristyl polyalkoxylated
vinyl ether, and mixtures thereof,
[0306] as well as mixtures of any of the above alkyl-polyether
acrylates, alkyl-polyether methacrylates, alkyl-polyether
acrylamides, alkyl-polyether methacrylamides, alkyl-polyether vinyl
esters, alkyl-polyether vinyl ethers, and/or alkyl-polyether vinyl
amides.
[0307] In one embodiment, the optional additional associative
monomer comprises one or more alkyl-polyalkoxylated (meth)acrylates
that comprise one linear or branched
(C.sub.5-C.sub.40)alkyl-polyethoxylated group, more typically
(C.sub.10-C.sub.22)alkyl-polyethoxylated group per molecule, such
as decyl-polyethoxylated (meth)acrylates, tridecyl-polyethoxylated
(meth)acrylates, myristyl-polyethoxylated (meth)acrylates,
cetyl-polyethoxylated (meth)acrylates, stearyl-polyethoxylated
(methyl)acrylates, eicosyl-polyethoxylated (meth)acrylates,
behenyl-polyethoxylated (meth)acrylates, even more typically
decyl-polyethoxylated methacrylates, tridecyl-polyethoxylated
methacrylates, myristyl-polyethoxylated methacrylates,
cetyl-polyethoxylated methacrylates, stearyl-polyethoxylated
methylacrylates, eicosyl-polyethoxylated methacrylates,
behenyl-polyethoxylated methacrylates, and mixtures thereof.
[0308] Anionic Monomers
[0309] In one embodiment, the acidic monomeric units each
independently comprise, per monomeric unit, at least one group
according to structure (A.I):
--R.sup.32--R.sup.31 (A.I)
wherein R.sup.31 is a moiety that comprises at least one carboxylic
acid, sulfonic acid, or phosphoric acid group, and R.sup.32 is
absent or is a bivalent linking group.
[0310] In one embodiment, R.sup.32 is O, --(CH.sub.2).sub.n--O--,
or is according to structure (structure (A.II):
##STR00006##
wherein:
[0311] n is an integer of from 1 to 6,
[0312] A is O or NR.sup.17, and
[0313] R.sup.17 is H or (C.sub.1-C.sub.4)alkyl.
[0314] In one embodiment, the acidic monomeric units each
independently comprise one or two carboxy groups per monomeric unit
and may, if the acidic monomeric unit comprises a single carboxy
group, further comprise an ester group according to
--CH.sub.2COOR.sup.33, wherein R.sup.33 is alkyl, more typically,
(C.sub.1-C.sub.6)alkyl.
[0315] The acidic monomeric units may be made by known synthesizing
techniques, such as, for example, by grafting of one or more groups
according to structure (A.I) onto a polymer backbone, such as a
hydrocarbon polymer backbone, a polyester polymer backbone, or a
polysaccharide polymer backbone. In the alternative, they may be
made by polymerizing a monomer comprising a reactive functional
group and at least one group according to structure (A.I) per
molecule.
[0316] In one embodiment, the reactive functional group is an
ethylenically unsaturated group so the monomer comprising a
reactive functional group is an ethylenically unsaturated monomer.
As a result the acidic monomer comprises at least one site of
ethylenic unsaturation, more typically, an .alpha.-,
.beta.-unsaturated carbonyl moiety, and at least one group
according to structure (A.I) per molecule and is copolymerizable
with the nonionic monomer(s) and the hydrophobic monomer(s).
[0317] In one embodiment the acidic monomer comprises one or more
ethylenically unsaturated monocarboxylic acid monomers according to
structure (A.III):
R.sup.34--R.sup.32--R.sup.31 (A.III)
[0318] wherein:
[0319] R.sup.31 and R.sup.32 are each as described above, and
[0320] R.sup.34 is a moiety having a site of ethylenic
unsaturation.
[0321] In one embodiment, the compound according to structure
(A.III) is an .alpha.-, .beta.-unsaturated carbonyl compound. In
one embodiment, R.sup.34 is according to structure (A.IV):
##STR00007##
wherein R.sup.19 is H or (C.sub.1-C.sub.4)alkyl.
[0322] Suitable acidic monomers include, for example, ethylenically
unsaturated carboxylic acid monomers, such as acrylic acid and
methacrylic acid, ethylenically unsaturated dicarboxylic acid
monomers, such as maleic acid and fumaric acid, ethylenically
unsaturated alkyl monoesters of dicarboxylic acid monomers, such as
butyl methyl maleate, ethylenically unsaturated sulphonic acid
monomers, such as vinyl sulfonic acid 2-acrylamido-2-methylpropane
sulfonic acid, and styrene sulfonic acid, and ethylenically
unsaturated phosphonic acid monomers, such as vinyl phosphonic acid
and allyl phosphonic acid, salts of any thereof, and mixtures of
any thereof. Alternatively, corresponding ethylenically unsaturated
anhydride or acid chloride monomers, such as maleic anhydride, may
be used and subsequently hydrolyzed to give a pendant moiety having
two acid groups. The preferred acidic monomeric units are derived
from one or more monomers selected from acrylic acid, methacrylic
acid, and mixtures thereof. Methacrylic acid has the following
formula A.V:
##STR00008##
[0323] In one embodiment, the additional nonionic monomeric units
each independently comprise, per monomeric unit, at least one group
according to structure (B.I):
--R.sup.42--R.sup.41 (B.I)
wherein R.sup.41 is alkyl, hydroxyalkyl, alkoxyalkyl, cycloalkyl,
aryl, arylalkyl, or aryloxy, and R.sup.42 is absent or is a
bivalent linking group.
[0324] In one embodiment, R.sup.41 is (C.sub.1-C.sub.22)alkyl,
(C.sub.1-C.sub.22)hydroxyalkyl, (C.sub.2-C.sub.22)alkoxyalkyl,
(C.sub.6-C.sub.24)cycloalkyl, (C.sub.6-C.sub.40)aryl, or
(C.sub.7-C.sub.40)arylalkyl, more typically
(C.sub.2-C.sub.12)alkyl.
[0325] In one embodiment, R.sup.41 is (C.sub.1-C.sub.22)alkyl, more
typically, (C.sub.1-C.sub.12)alkyl.
[0326] In one embodiment, R.sup.42 is O, --(CH.sub.2).sub.n--O--,
wherein n is an integer of from 1 to 6, or is according to
structure (B.II):
##STR00009##
wherein: n is an integer of from 1 to 6,
A is O or NR.sup.17, and
[0327] R.sup.17 is H or (C.sub.1-C.sub.4)alkyl.
[0328] The nonionic monomeric units may be made by known
synthesizing techniques, such as, for example, by grafting of one
or more groups according to structure (B.I) onto a polymer
backbone, such as a hydrocarbon polymer backbone, a polyester
polymer backbone, or a polysaccharide polymer backbone, or a
backbone made by polymerization with, for example, the above
described acidic monomers and hydrophobic monomers, and at least
one other monomer selected from monomers comprising a reactive
functional group and at least one group according to structure
(B.I) per molecule. Alternatively, the nonionic monomeric units may
simply be non-grafted portions of a polymer backbone.
[0329] In one embodiment, the nonionic monomeric units are derived
from a nonionic monomer, for example, ethyl acrylate, comprising a
reactive functional group and a group according to structure (B.I),
and copolymerizable with the acidic monomers and hydrophobic
monomers.
[0330] In one embodiment, the reactive functional group of the
nonionic monomer is an ethylenically unsaturated group and the
nonionic monomer is an ethylenically unsaturated monomer comprising
at least one site of ethylenic unsaturation, more typically, an
.alpha.-, .beta.-unsaturated carbonyl moiety and at least one group
according to structure (B.I) per molecule.
[0331] In one embodiment, the nonionic monomer comprises one or
more compounds according to structure (B.III):
R.sup.43--R.sup.42--R.sup.41 (B.III)
[0332] wherein:
R.sup.41 and R.sup.42 are each as described above, and R.sup.43 is
a moiety having a site of ethylenic unsaturation.
[0333] In one embodiment, the compound according to structure
(B.IIII) is an .alpha.-, .beta.-unsaturated carbonyl compound. In
one embodiment, R.sup.43 is according to structure (B.IV):
##STR00010##
wherein R.sup.19 is H or (C.sub.1-C.sub.4)alkyl.
[0334] Suitable nonionic monomers include unsaturated monomers
containing at least one group according to structure D.I per
molecule, including (meth)acrylic esters such as: methyl
(meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate,
isobutyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl
(meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate
isobornyl (meth)acrylate, benzyl (meth)acrylate, hydroxyethyl
(meth)acrylate, hydroxypropyl (meth)acrylate, methoxyethyl
(meth)acrylate, ethoxyethyl (meth)acrylate, phenoxyethyl
(meth)acrylate, tetrahydrofurfuryl (meth)acrylate, glycidyl
(meth)acrylate, dimethylaminoethyl (meth)acrylate,
diethylaminoethyl (meth)acrylate, tert-butylaminoethyl
(meth)acrylate, and acetoxyethyl (meth)acrylate, (meth)acrylamides
such as, (meth)acrylamide, N-methylol (meth)acrylamide,
N-butoxyethyl (meth)acrylamide, N,N-dimethyl (meth)acrylamide,
N-isopropyl (meth)acrylamide, N-tert-butyl (meth)acrylamide,
N-tert-octyl (meth)acrylamide, and diacetone (meth)acrylamide,
vinyl esters such as vinyl acetate, vinyl propionate, vinyl
2-ethylhexanoate, N-vinylamides such as: N-vinylpyrrolidione,
N-vinylcaprolactam, N-vinylformamide, and N-vinylacetamide, and
vinyl ethers such as, methyl vinyl ether, ethyl vinyl ether, butyl
vinyl ether, and hydroxybutyl vinyl ether, and ethylenically
unsaturated aryl compounds, such as styrene.
[0335] A method for the preparation of self-assembled particles
induced macromolecular polymeric emulsifier by RAFT, characterized
by comprising the steps of: (1) in two different hydrophilic and
hydrophobic monomers as the raw material, is formed by amphiphilic
molecules RAFT polymerization; (2) amphiphilic macromolecular chain
transfer agent and a crosslinking agent RAFT polymerization
reaction solvent, use of a crosslinking agent after crosslinking
the polymeric core formed by the difference in solvent solubility
directly induce the formation of colloidal particles, the reaction
solution was dialyzed to remove unreacted monomers, to obtain
colloidal particles dispersion; (3) to the dispersion of step (2)
of the colloidal particles obtained as aqueous phase, and the oil
phase were mixed by a volume ratio,
[0336] Polymer Compositions
[0337] In one embodiment, the polymer composition is in the form of
an aqueous polymer dispersion, typically having a solids content
including the polymer and any surfactants that may be present and
based on the total weight of the polymer dispersion, of up to about
60 wt % and, more typically about 20 to about 50 wt %.
[0338] Experiments
[0339] PAA-Xa (i.e, PAA-Xanthate Moiety)
[0340] In a typical procedure, initial water, ethanol, Rhodixan A1,
initial initiator V50 and 10 wt % of total acrylic acid, were
introduced in a glass reactor, equipped with a mechanical stirrer
and a condenser. After deoxygenation the mixture was heated and an
aqueous solutions of acrylic acid and initiator were introduced
separately in the reactor. The mixture was kept at polymerization
temperature for several hours and then cooled down to room
temperature.
TABLE-US-00001 Reactant 16PDL019 16PDL021 16PDL022 Acrylic Acid
Initial 110 110 110 Feed (41 wt %) 990 990 990 Water 225.65 325.93
192.23 V50 Initial 0.479 1.196 0.239 Feed (6 wt %) 2.991 7.477
1.495 Ethanol 301.57 435.58 256.90 Rhodixan A1 45.83 114.57 22.91
M.sub.n (kg/mol) 5.2 2.2 10.7 PDI 1.37 1.37 1.29 [AA].sub.residual
490 290 1020 (ppm)
[0341] PAM-Xa
[0342] In a typical procedure, initial water, ethanol, Rhodixan A1,
initiator ACP and 10 wt % of total acrylamide (50 wt % in water)
were introduced in a glass reactor, equipped with a mechanical
stirrer and a condenser. After deoxygenation by nitrogen bubbling,
the mixture was heated to greater than 50.degree. C. and acrylamide
was introduced in the reactor for greater than 1 hour. The mixture
was kept at polymerization temperature and then cooled down to room
temperature.
TABLE-US-00002 Reactant 16EVN016 Acrylamide Initial 80 Feed (50 wt
%) 720 Water 203.42 ACP 1.40 Ethanol 250.85 Rhodixan A1 34.77
M.sub.n (kg/mol) PDI [AM].sub.residual (ppm)
[0343] PDMA-Xa
[0344] In a typical procedure, initial water, ethanol, Rhodixan A1,
and 15 wt % of total dimethylacrylamide were introduced in a glass
reactor, equipped with a mechanical stirrer and a condenser. After
deoxygenation by nitrogen bubbling, aqueous solutions of ammonium
persulfate APS (20 wt %), and hydroxymethane sulfonic acid sodium
salt Dihydrate NaFS (2.5 wt %) were introduced shotwise. At the
same time aqueous solution of DMA (40 wt %) and NaFS (2 wt %) were
introduced in the reactor. The mixture was kept at polymerization
temperature for more than 1 hour and then cooled down to room
temperature.
TABLE-US-00003 Reactant 16DTE032 Dimethylacrylamide Initial 67.5
Feed (40 wt %) 382.5 Water 126.83 APS 2.53 NaFS Initial 0.0203 Feed
(40 wt %) 0.486 Ethanol 124.34 Rhodixan A1 46.87 M.sub.n (kg/mol)
PDI [DMA].sub.residual (ppm)
[0345] Latex Synthesis Via Seed:
[0346] De-ionized water and the macro CTA PAM-Xa
(Polyacrylamide-xanthate) were added to a suitable reactor for
emulsion polymerization equipped with agitation, heating and
cooling means with a slow continuous nitrogen purge. Under
continuous agitation, the temperature of the reactor was raised and
a monomer mixture (9 g) of vinyl acetate, butyl acrylate, and
acrylic acid was added to the reactor.
[0347] Once the temperature of the reactor had stabilized to less
than 40.degree. C., a solution of sodium metabisulfite (6.13 g) was
added to the reactor, than a solution of ammonium persulfate was
added.
[0348] The seed was kept at constant temperature and there was no
observable change in color (bluish); however a slight exotherm of
1-2.degree. C. was noticeable. A small sample was removed to check
for particle size. The continuous addition of the remaining monomer
mixture (171 g) was completed for several hours--a continuous
addition of the remaining solution of ammonium persulfate (24.3 ml)
and sodium metabisulfite. Once the monomer addition was completed,
the rest of the remaining initiators were fed over a period of 30
minutes.
[0349] A total of 3 ml of FeCl3 solution (0.01 g of FeCl3 was
diluted in 6.5 g of deionized water) was added (in 2 lots at 10
minute interval) to the reactor after the monomer additions with
reactor. An hour into the addition of monomers and initiators, the
temperature of the reactor was slowly. At the end of the monomer
and initiators additions, the temperature of the reactor was
increased slowly over 40 minutes to 80.degree. C. The reactor was
cooled and the resulting latex was filtered through a 136 um
polyester filter. The polymer dispersion obtained had a solid
content of 39.65%, and the average particle size was 113.0 dnm.
(diameter nm)
[0350] The physical properties of the latex are reported in table
1. Water sensitivity test is reported in table 1.1.
[0351] The solids content was determined in general by drying about
1 g of latex in an open aluminum pan in a drying oven set at
120.degree. C. for an hour. The solids content was calculated by
averaging three separate measurements.
[0352] The particle size of the resulting latex was determined by
using Zetasizer Nano S from Malvern Instruments Ltd with standard
methods and procedures for operation of the equipment. The sample
was prepared by using one drop of latex in about 20 g deionized
water. The sample was then well mixed before placing it in the
cuvette.
[0353] The mechanical stability of the latex was evaluated by
placing about 160 g of latex in a Commercial Waring Blender (single
speed at 16,000 RPM) and blends the latex for five minutes. Failure
of the latex is at the point latex became unstable and coagulates.
If after 5 minutes, the latex did not coagulate, the content is
filtered through a 136 um polyester filter.
[0354] The freeze-thaw stability of the aqueous polymer dispersion
was measured by ASTM standard test method D-2243. The procedure for
this ASTM method is as follows: the samples were placed in the
freezer overnight at 0.degree. F. (-18.degree. C.) for 17 hours.
The samples were then removed from the freezer the next day and
were allowed to "thaw out" at room temperature for 7 hours. The
samples were then well mixed by hand using a spatula before
measuring the viscosity.
[0355] For salt tolerance test, a 5% wt. solution of CaCl2 was
prepared in deionized water. About 60 g of latex was weighted out
in a 200 mL plastic beaker. The latex solution was placed under a
stir shaft and started mixing. Added drop wise of the CaCl2
solution into the latex and record the gram of solution was used.
The solution is failed if the latex started to coagulate.
[0356] The viscosity of the resulting latex was determined by using
a Brookfield DV2T Extra viscometer with spindle #31. The viscometer
was operated at room temperature and at speed of 10 RPM.
[0357] The surface tension of the resulting latex was determined by
using a KSV Tensiometer with standard procedure for the operation
of the equipment. About 60 g of Latex was measured in a 100 g dish,
and a DuNouy ring was used to measure the surface tension.
[0358] Water sensitivity of the resulting latex was determined by
the following three methods:
[0359] Method 1: The resulting latex was draw down on a glass plate
using a 8 ml bar for the film formation. After the film was dried
in the room temperature for 2 days, several water drops were
pipetted onto the dried film. Observe the discoloration after 10
minutes, and it was ranked based on 1 (fully discolored)-5 (no
discoloration) scale.
[0360] Method 2: The resulting latex from method 1 was dried for 5
hours from the water spotting test. A water bath was prepared at
room temperature, and parts of the films were submerged under the
water. The films were checked after 24, 48, 72, and 96 hours.
Again, same ranking was given as in method 1.
[0361] Method 3: Only films had the ranking of 4 or 5 from method 2
was tested under this method. Method 3 was adaptation of ASTM
standard test method D 2247-15. The procedure for this method is as
follows: A pan was filled with water and it was heated on a hot
plate. The films were exposed to the heated and saturated mixture
of air and water vapor for an hour. The films were ranked based on
the same ranking as method 1.
Example 1.1 (1298-182)
[0362] The preparation of example 1.1 was effected analogously to
example 1 as repeat example. All processing was comparable.
[0363] The polymer dispersion obtained had a solid content of
39.17% and the average particle size was 119.4 dnm. Various
physical properties of the latex are reported in table 1. Water
sensitivity test is reported in table 1.1.
Example 1.2 (1341-05)
[0364] The preparation of example 1.2 was effected analogously to
example 1. The process was modified to have an improved process for
monomer conversion.
[0365] The polymer dispersion obtained had a solid content of
42.55% and the average particle size was 124.1 dnm. Various
physical properties of the latex are reported in table 1. Water
sensitivity test is reported in table 1.1.
Example 1.3
[0366] (S1313-141)
[0367] The preparation of example 1.3 was effected analogously to
example 1, except 156.49 g of deionized water and 67.36 g (16%
Based on Total Monomer) of PAM-Xa were initially added to the
kettle charge. And a change in initiators from sodium
metabisulphite to ascorbic acid, with a total of 0.162 g of
ascorbic acid and 0.55 g of sodium bicarbonate in 30 g of deionized
water.
[0368] The seed was kept at constant temperature for an hour.
Evidence of the polymerization was observed by the appearance of
white latex color 10 minutes into the monomer addition. The
continuous addition of the remaining monomer mixture (171 g)
occurred over several hours. 2 ml of FeCl3 solution was then added
to the reactor. At end of the monomer and initiators additions, the
temperature of the reactor was increased slowly to around
80.degree. C. After cooling the reaction, 3 g of 20% ammonium
hydroxide solution was added to the polymer dispersion.
[0369] The polymer dispersion obtained had a solid content of
29.91%, and the average particle size was 59.28 nm. Various
physical properties of the latex are reported in table 1. Water
sensitivity test is reported in table 1.1.
Example 1.4
[0370] (1313-134)
[0371] The preparation of example 1.4 was effected analogously to
example 1, except 174.05 g of deionized water and 68.8 g (16% Based
on Total Monomer) of PAM-Xa were initially added to the kettle
charge under continuous agitation. Monomer mixture was prepared
under the same manner, except the monomer seed was the only
composed of butyl acrylate and acrylic acid. A solution of ammonium
persulfate was added to the kettle charge, followed by the monomer
seed [5% of the butyl acrylate and acrylic acid monomer
mixture].
[0372] The seed was kept at constant temperature for over 50
minutes. The continuous addition of the sodium bicarbonate (0.50 g
of sodium bicarbonate was dissolved in 42.49 g of deionized water)
was started to complete in three hours.
[0373] Fifty minutes into monomer addition, the temperature of the
reactor was raised to 70.degree. C. An hour later, the monomer
addition was turned off due to a noticeable excessive exotherm and
heavy reflux of monomers. Consequently also 80.97 g of deionized
water was added, and the temperature of the reactor was decreased
to 68.5.degree. C. Monomer addition was resumed 45 minutes later.
The polymer dispersion obtained had a solid content of 35.27%, and
the average particle size was 78.3 dnm. Various physical properties
of the latex are reported in table 1. Water sensitivity test is
reported in table 1.1.
Example 1.5
[0374] (1298-176)
[0375] The preparation of example 1.5 was effected analogously to
example 1, except 188.40 g of deionized water and 34.37 g (8% BOTM)
of PAM-Xa were initially added to the kettle charge under
continuous agitation. A monomer mixture was added to the reactor,
followed by a solution of ammonium persulfate (6.13 g) [20% of the
total solution of ammonium persulfate (0.17 g) and sodium
bicarbonate (0.50 g) dissolved in deionized water (30.0 g)]. The
seed was kept at constant temperature. Both monomer and initiator
additions were kept at constant temperature.
[0376] The polymer dispersion obtained had a solid content of
42.68%, and the average particle size was 184.0 dnm. Various
physical properties of the latex are reported in table 1. Water
sensitivity test is reported in table 1.1.
Example 1.6
[0377] [S1336-88]
[0378] Deionized water (158.9 g.) with PAM-Xa (34.37 g.) was added
to a suitable reactor equipped with agitation, heating and cooling
means with a slow continuous nitrogen purge and stirred
continuously at a slow agitation. A 5% monomer mixture of vinyl
acetate, butyl acrylate and acrylic acid was added to the reactor
for the seed stage. Then sodium metabisulfite solution, followed by
ammonium persulfate solution, was added to the reactor.
[0379] The seed was allowed to react at constant temperature and a
faint light bluish color was observed after an hour. Before
starting the feed, FeCl3 was added to the reactor. The latex was
cooled to below 40.degree. C. and filtered through a 136 um
polyester filter.
[0380] The final latex solids were 44.66%, pH of 1.89, viscosity of
2368 cps and particle size of 89.23 nm. The pH of the final latex
was 1.89, and a small sample was taken and pH increased to 7.76 by
adding ammonium hydroxide. The sample with higher pH exhibited very
thick and gel-like properties. Physical properties of the latex are
reported in table 1. Water sensitivity test is reported in table
1.1.
TABLE-US-00004 TABLE 1 PAM-XA in Va/Ba/AA system Monomer Particle
Surface Method % BOTM % size Solids Mechanical Tension Viscosity
Salt of Example PAM-XA seed (d.nm) % stability pH Freeze/thaw
(mN/m) (cP) Tolerance intiation 1 8 5 113.0 39.65 Passed 4.76 F
50.254 198 Did not Redox coagulate 1.1 8 5 119.4 39.17 -- 4.43 --
35.09 -- -- Redox 1.2 8 5 124.1 42.55 passed 4.79 -- 50.36 1704 --
Redox 1.3 16 5 59.28 29.91 passed 4.64 F 43.73 519 -- Redox 1.4 16
5 78.3 35.27 passed 4.75 -- -- >3000 -- Thermal 1.5 8 5 184
42.68 passed 4.71 -- 53.32 393.0 -- Thermal 1.6 8 5 89.26 44.66
passed 1.89 -- -- 2368 -- Redox Comparative (surfactant) 5 110.5
43.20 passed 9.01 -- 31.502 93 Did not Thermal example 1 coagulate
Comparative (surfactant) 5 113.4 47.0 failed 8.82 -- 208 -- Redox
example 2
TABLE-US-00005 TABLE 1.1 Water sensitivity for films made from
PAM-XA in VA/BA/AA System Water bath test Example Water spot test
(after 96 hours) Water vapor test 1 5 5 5 1.1 5 5 5 1.2 5 5 5 1.3 2
2 N/A 1.4 2 3 N/A 1.5 1.5 1.5 N/A 1.6 5 Comparative 3 1 1 example 1
Comparative 2 example 2
Example 2 (PAM in all Acrylic) (S1341-39)
[0381] Preparation of the Latex Via Seed:
[0382] Deionized water (238.38 g) was initially added to a suitable
reactor for emulsion polymerization equipped with agitation,
heating and cooling means with a slow continuous nitrogen purge.
Under continuous agitation, the temperature of the reactor was
raised and the macro CTA PAM-Xa (76.8 g) was added to the reactor.
Once the temperature was stabilized at constant temperature, the
monomer mixture methyl acrylate, butyl acrylic, and acrylic acid
was added. Then a solution of ammonium persulfate (0.37 g of
ammonium persulfate was dissolved in 1.187 g of deionized water)
was added to the reactor. Evidence of the polymerization was
observed by the appearance of the light blue tint color in the
reactor after 1 minutes of the initiator addition.
[0383] For this particular example, the resulting latex dispersion
had reached to theoretical solid content right after addition of
monomer. The reaction was then cooled and the resulting latex was
bottled (No filter was used due to high viscosity). The polymer
dispersion obtained had a solid content of 45.65% and the average
particle size was 106.8 dnm. Various physical properties of the
latex are reported in table 2, and all test methods are the same as
in example 1, except viscosity. Instead of using Brookfield DV2T
Extra viscometer with spindle #31, this run was tested using
Brookfield Model DV II with spindle LV 2C and 10 RPM.
TABLE-US-00006 TABLE 2 PAM-XA in all acrylic system BOTM Particle
Surface % PAM- Monomer size Freeze/ Tension Viscosity Salt Example
XA seed % (d nm) Solids % Mecstability pH thaw (mN/m) (cP)
Tolerance 2 16 5 106.8 45.65 -- 2.56 -- N/A 17790 -- (latex too
thick)
[0384] The film of the latex was not prepared, as the latex was too
high in viscosity.
Example 3 (PAA-XA in Styrene/BA) (S1313-55)
[0385] Preparation of the Latex Via Seed:
[0386] Deionized water (298.62 g) was initially added to a suitable
reactor for emulsion polymerization equipped with agitation,
heating and cooling means with a slow continuous nitrogen purge.
Under continuous agitation, the temperature of the reactor was
raised, a monomer mixture of styrene and butyl acrylate was added
to the reactor, followed by the macro CTA PAA-XA (polyacrylic
acid-xanthate, 50% solids). Once the temperature of the reactor had
stabilized, a solution of ammonium persulfate was added to the
reactor. Evidence of the polymerization was observed by the
appearance of the blue tint color in the reactor after 5 minutes of
the initiator addition. Continuous addition of the remaining
monomer mixture was started to complete over several hours at
varying rates.
[0387] When the monomer addition was finished, a small sample of
aqueous polymer dispersion was obtained to do a solid content. If
the solid content has reached to theoretical solid, then the
reaction was cooled, and the resulting latex was filtered through a
136 um polyester filter. If the solid content was not at the
theoretical solid, then the aqueous polymer dispersion was further
reacted until the theoretical solid is reached.
[0388] For this particular example, the latex polymer dispersion
had reached to theoretical solid content right after addition of
monomer. The reaction was then cooled and the resulting latex was
filter using 136 um polyester filter. The polymer dispersion
obtained had a solid content of 41.063% and the average particle
size was 108.8 dnm. Various physiochemical properties of the latex
are reported in table 3, and all test methods are the same as in
example 1, except viscosity. Instead of testing at 10 RPM, the
examples in 2 were tested at 20 RPM.
[0389] For water sensitivity test, only method 1 was applied, and
the results were based on 2 minutes time frame. The results of the
latex are recorded in table 3.1.
Example 3.1 (S1313-67)
[0390] The preparation of example 3.1 was effected analogously to
example 3. All process was comparable.
[0391] The polymer dispersion obtained had a solid content of
41.77% and the average particle size was 147.04 dnm. Various
physical properties of the latex are reported in table 3. Water
sensitivity test is reported in table 3.1.
Example 3.2 (1298-159)
[0392] The preparation of example 3.2 was effected analogously to
example 3, except only 2.8 g (2% of the total monomer weight) of
monomer mixture was initially added to the reactor, and the
ammonium persulfate solution was continuously added along with the
monomer mixture. The aqueous polymer dispersion was further heated
at constant temperature for an hour before cooling. The polymer
dispersion obtained had a solid content of 38.99% and the average
particle size was 116.3 dnm. Various physical properties of the
latex are reported in table 3. Water sensitivity test is reported
in table 3.1.
Example 3.3 (1313-92)
[0393] The preparation of example 3.3 was effected analogously to
example 3. The weight percentage of this example was 70% of the
original weight. Except only 0.7 g (0.5% of the total monomer
weight) of monomer mixture was initially added to the reactor. No
evidence of blue tint was observed after the addition of the
ammonium persulfate solution.
[0394] However, evidence of the polymerization was observed by the
appearance of the light blue color in the reactor 5 minutes after
the monomer addition. The polymer dispersion obtained had a solid
content of 39.21% and the average particle size was 197.8 dnm.
Various physical properties of the latex are reported in table 3.
Water sensitivity test is reported in table 3.1.
Example 3.4 (1313-58)
[0395] The preparation of example 3.4 was effected analogously to
example 3, except only 32.0 g (8% based on the total monomer) of
PAA-XA was initially added to the reactor. The aqueous polymer
dispersion was further heated for an hour at high temperature
before cooling.
[0396] The polymer dispersion obtained had a solid content of
39.93% and the average particle size was 155.3 dnm. Various
physical properties of the latex are reported in table 3. Water
sensitivity test is reported in table 3.1.
Example 3.5 (1313-49)
[0397] The preparation of example 3.5 was effected analogously to
example 3. Except only 4.0 g (2% of the total monomer weight)
monomer mixture was initially added to the reactor. The aqueous
polymer dispersion was further heated for an hour at high
temperature before cooling. The polymer dispersion obtained had a
solid content of 39.55% and the average particle size was 120.6
dnm. Various physical properties of the latex are reported in table
3. Water sensitivity test is reported in table 3.1.
Example 3.6 (1313-45)
[0398] The preparation of example 3.6 was effected analogously to
example 3. Except only 20.0 g (10% of the total monomer weight)
monomer mixture was initially added to the reactor.
[0399] The aqueous polymer dispersion was further heated and after,
a solution of ammonium persulfate was added to the reactor to
increase the rate of polymerization. The reactor was heated for
additional hour at high temperature.
[0400] The polymer dispersion obtained had a solid content of
40.43% and the average particle size was 255.4 dnm. Various
physical properties of the latex are reported in table 3. Water
sensitivity test is reported in table 3.1.
TABLE-US-00007 TABLE 3 PAA-XA in styrene/ba system % BOTM Particle
Surface PAA- monomer size Mechanical Freeze/ Viscosity Tension Salt
Example XA seeds % (d nm) Solids % stability pH thaw (cP) (mN/m)
tolerance 3 16 5 108.8 41.063 passed 2.02 F 55 63.702 -- 3.1 16 5
147.04 41.77 Passed -- F 24 54.571 -- 3.2 16 2 116.3 38.99 passed
2.19 -- 21 59.629 -- 3.3 16 0.5 197.8 39.21 passed 2.25 P 12 50.405
-- 3.4 8 5 155.3 39.93 Failed 2.03 F 21 58.825 -- 3.5 16 2 120.6
39.55 passed 2.02 -- 33 50.155 Did not coagulate 3.6 16 10 255.4
40.43 passed 1.9 p 15 54.215 --
TABLE-US-00008 TABLE 3.1 Water sensitivity test for films made from
PAA-XA in styrene/ba system % BOTM monomer Example PAA-XA seeds %
Water spot test 3 16 5 5 3.1 16 5 5 3.3 16 2 5 3.4 16 0.5 1 3.4 8 5
4.5 3.5 16 2 5 3.6 16 10 1
Example 4 (PDM in Styrene/BA)
[0401] (1341-01)
[0402] Preparation of the Seed:
[0403] Deionized water (315.05 g) was initially added to a suitable
reactor for emulsion polymerization equipped with agitation,
heating and cooling means with a slow continuous nitrogen purge.
Under continuous agitation, the temperature of the reactor was
raised and a monomer mixture of styrene and butyl acrylate was
added to the reactor, followed by the macro CTA PDM-XA
(polydimethaminoacrylamide-xanthate). Once the temperature of the
reactor had stabilized, a solution of ammonium persulfate was added
to the reactor. Evidence of the polymerization was observed by the
appearance of the blue tint color in the reactor after 2 minutes of
the initiator addition.
[0404] The seed was kept at high temperature for an hour. The latex
had the solid content of 39.15% by weight, based on the total
weight of the aqueous dispersion. The mean particle size of the
polymer was 124.4 dnm.
[0405] Various physical properties of the latex are reported in
table 4. Water sensitivity test is reported in table 4.1. All test
methods are followed in example 1.
Example 4.1 (S1341-43)
[0406] The preparation of example 4.1 was effected analogously to
example 4. Except only 32.9 g of macro CTA PDM-XA
(polydimethaminoacrylamide) was added to the reactor.
[0407] The aqueous polymer dispersion did not reach to theoretical
solid after the monomer addition, and it was further heated at high
temperature. A solution of ammonium persulfate was added to the
reactor to increase the solids. The aqueous polymer dispersion was
further heated for additional hours before cooling, and the
resulting latex was filter using 136 um polyester filter.
[0408] The particle size of the resulting latex was 603.2 dnm.
However, the latex was found to be unstable overtime.
TABLE-US-00009 TABLE 4 PDM-XA in Styrene/BA system % BOTM Particle
Surface PDM- monomer size Mechanical Freeze/ Tension Viscosity Salt
Example XA seeds % (d nm) Solids % stability pH thaw (mN/m) (cP)
Tolerance 4 16 5 124.4 39.15 passed 2.47 F 60.296 306 passed 4.1 8
5 603.2 Unstable -- -- -- -- -- --
TABLE-US-00010 TABLE 4.1 PDM-XA in Styrene/BA system Water bath
test Example Water spot test (after 96 hours) Water vapor test 4 4
5 5
Comparative Example 1 (1298-102)
[0409] The resulting latex was used as a control for example 1,
1.1, 1.2, 1.3, 1.4, 1.5, and 1.6.
[0410] Deionized water (114.2 g) and Tridecyl 30 EO sulfate (4.96
g) [0.70% Based on the total monomer] were initially added to a
suitable reactor for emulsion polymerization equipped with
agitation, heating and cooling means with a slow continuous
nitrogen purge. Under continuous agitation, the temperature of the
reactor was raised, and a monomer pre-emulsion [deionized water,
Tridecyl 30 EO sulfate, methyl methacrylate, butyl acrylate, and
methacrylic acid] was added to the reactor (the pre-emulsion was
neutralized to a pH about 7 with 20% ammonium hydroxide).
[0411] Once the temperature of the reactor had stabilized, a
solution of ammonium persulfate was added to the reactor. The seed
was kept at constant temperature and a small sample was removed to
check for particle size. After the initiator addition completed,
the temperature of the reactor was raised and held it for
additional 30 minutes. The reactor was then cooled and the pH of
the aqueous polymer dispersion was then adjusted to pH 9.01.
[0412] The resulting latex product was completely removed from the
reactor and filtered through a 136 um polyester filter.
[0413] The latex had the solid content of 43.20% by weight, based
on the total weight of the aqueous dispersion. The mean particle
size of the polymer was 110.5 dnm.
[0414] Various physical properties of the latex are reported in
table 1. Water sensitivity test is reported in table 1.1.
Comparative Example 2: [S1336-75]
[0415] The resulting latex was used as a control for example 1,
1.1, 1.2, 1.3, 1.4, 1.5, and 1.6.
[0416] Deionized water (78 g), Sodium C14-16 Olefin sulfonate (2.5
g), sodium bicarbonate (0.125 g), and ferric chloride (1.25 g)
[0.005 g FeCl3 in 5 ml of water] were added to a suitable reactor
for emulsion polymerization equipped with agitation, heating and
cooling means, and a slow continuous nitrogen purge. Under
continuous agitation, the temperature of the reactor was raised and
5% of the monomer pre-emulsion (17.49 g) (consisting of deionized
water (90 ml), Sodium C14-16 Olefin sulfonate (9.375 g), sodium
bicarbonate (0.375 g), vinyl acetate (147.5 g), butyl acrylate (100
g), and acrylic acid (2.5 g) was added. The pre-emulsion was judged
to be stable before being added to the reactor. After 5 minutes,
20% (8.10 g) of a solution of sodium metabisulfite (0.875 g of
sodium metabisulfite dissolved in 40.0 g of deionized) was added to
the reactor, followed by 20% (8.04 g) of a solution of ammonium
persulfate (1.276 g of ammonium persulfate dissolved in 40.0 g of
deionized water).
[0417] The seed was allowed to react at constant temperature
(particle size z-average of 74.94 dnm). Redox post addition was
then initiated, with a solution of sodium metabisulfite (0.15 g)
and deionized water (2.5 ml), followed by a solution of tert-butyl
hydro peroxide (0.215 g) and water (2.5 ml), added slowly to avoid
to avoid any excessive exotherms. The latex was cooled and filtered
through a 136 um polyester filter. The solids were at 47.0%, pH of
5.22 with particle size of 113.4 dnm. And the latex was adjusted
with ammonium hydroxide to a pH of 8.82 that viscosity of 208
cps.
Example 5 (S1341-100)
[0418] De-ionized water and the Macro CTA PAM-Xa (Polyacrylamide
xanthate) were added to a suitable reactor for emulsion
polymerization equipped with agitation, heating and cooling means
with a slow continuous nitrogen purge. Under continuous agitation,
the temperature of the reactor was raised and a monomer mixture of
vinyl acetate, butyl acrylate, and acrylic acid was added to the
reactor.
[0419] Once the temperature of the reactor had stabilized, a
solution of sodium metabisulphite was added to the reactor, after
which time a solution of ammonium persulfate was added. The seed
was kept at constant temperature for 40 minutes. There was no
observable change in color (bluish); however a slight exotherm of
1-2.degree. C. was noticeable. A small sample was removed to check
for particle size.
[0420] 3 ml of a FeCl3 solution was added to the reactor. An hour
into the addition of monomers and initiators, the temperature of
the reactor was slowly raised.
[0421] The reactor was then cooled and the resulting latex was
filtered through a 136 um polyester filter. The polymer dispersion
obtained had a solid content of 44.34%, and the average particle
size was 121.7 dnm.
Comparative Example 5C1 (S1336-68)
[0422] Deionized water, Sodium C14-16 Olefin sulfonate, and sodium
bicarbonate were added to a suitable reactor for emulsion
polymerization equipped with agitation, heating and cooling means
with a slow continuous nitrogen purge. Under continuous agitation,
the temperature of the reactor was raised and a monomer
pre-emulsion [deionized water, Sodium C14-16 Olefin sulfonate,
sodium bicarbonate, vinyl acetate, butyl acrylate, and acrylic
acid] was added to the reactor (the pre-emulsion was stabilized
before adding), followed by a solution of ammonium persulfate. The
seed was kept at constant temperature for 15 minutes. The polymer
dispersion obtained had a solid content of 47.89%, the average
particle size was 103.3 dnm and a pH of 4.95.
Comparative Example 5C2: Encor 310 from Arkema as Commercial Vinyl
Acrylic Binder Control
TABLE-US-00011 [0423] TABLE 5 Latex properties: Particle Size, d nm
Solids, % pH coagulum Viscosity Example 5 121.7 44.34 4.94 0.114
549.0 Comparative 103.3 47.89 4.95 0.01 3040 example 5C1
Comparative example 5C2 (commercial latex)
[0424] Paint Formulation:
[0425] The latex sample prepared from example 5, the comparable
example 5C1, and 5C2 were used to prepare architectural paints. The
paint formulation is shown in the following table 5.1.
TABLE-US-00012 TABLE 5.1 Paint formulation. Comparative Comparative
Raw Material Example 5 example 5C1 example 5C2 Pigment Grind Water
10.76 10.76 10.76 Natrosol Plus 330 0.13 0.13 0.13 AMP-95 0.12 0.12
0.12 Acticide BW-20 0.18 0.18 0.18 Dispersant 0.63 0.63 0.63
Defoamer 0.18 0.18 0.18 Wetting agent 0.27 0.27 0.27 CaCO3 #10
white 10.76 10.76 10.76 Kaolin 5.65 5.65 5.65 Organic Clay 0.36
0.36 0.36 Letdown Ti-Pure R-746 23.31 23.31 23.31 Water 6.53 6.53
6.53 Latex Resins 32.73 32.73 32.73 Coalescent 1.35 1.35 1.35
AMP-95 0.05 0.05 0.05 Defoamer 0.27 0.27 0.27 Thickner 0.13 2.39
3.14 Water 5.24 1.33 3.58 Total 100 100 100 Properties: PVC, %
40.46
[0426] The liquid paint properties were measured in the following
table 5.2.
TABLE-US-00013 TABLE 5.2 Liquid Paint Performance Properties
Samples Comparative Comparative Example 5 example 5C1 example 5C2
Initial properties KU viscosity 105 100.2 101.1 ICI viscosity,
poise 1.2 1.6 1.4 pH 8.61 9.12 9.02 Equilibrated properties KU
viscosity 119 110 125/121 ICI viscosity, poise 2.1 1.8 1.34 pH 8.28
9.34 9.01
[0427] Dry paint performance was further evaluated and the
properties were given in table 5.3.
TABLE-US-00014 TABLE 5.3 Properties of dry paint Samples
Comparative Comparative Example 5 example 5C1 example 5C2 Gloss,
60.degree. 5.0 5.0 5.0 Sag 24 12 12 Flow 3 7 8 Opacity -Hiding
97.85 97.21 96.59 Block Resistance 1 day, RT/Oven 10/7 10/2 6/2 7
days, RT/Oven 10/9 10/6 9/4 Stain Test % removed hydrophobic 58.33
20.83 45 % removed hydrophilic 81.25 72.5 37.5
[0428] Referring to Table 5.3, Sag refers to the resistance a
coating has to undesired flow when applied to a surface. For
example, when paints are painted on a wall for instance, they tend
to sag when first applied, and then flow. The optimized paint
usually has good sag and flow resistance. The coating made in
Example 5 exhibited showed a higher sag value as compared to the
comparative example (wherein the sag resistance equals twice as
better resistance).
[0429] Opacity: the term used to describe the hiding strength of
paint films. It is an indication of how well the pigments are
dispersed; the higher the percentage, >96%, the better the
hiding.
[0430] Block Resistance: This method is used to test the resistance
of dry paint films to adhere to each other. When two dry paints
come together in contact with each other, the paints exhibit the
undesired effect of blocking, i.e., sticking to itself/each other.
Referring back to Table 5.3, a Block value of 10 means the block
resistance is very good, indicating the two films do not stick
together. A block Value 1 means the two dry films stick together
when in contact, so it is the least favorable value. As seen in the
table, the Block resistance of the coatings made in Example 5 show
block values of 7 and 9 out of 10, for 1 day and 7 days,
respectively. By contrast, the Block resistance of comparative
example 5C1 shows block values of 2 and 6 out of 10, for 1 day and
7 days, respectively. By contrast, the Block resistance of
comparative example 5C1 shows block values of 2 and 4 out of 10,
for 1 day and 7 days, respectively. Both comparative examples are
far lower (i.e., worse) than the block values for example 5.
[0431] Stain test is to test the different hydrophobic (oil based
material like lip sticks) and hydrophilic (water based material
like tea) materials on the dry paints. The percentage removed
indicates how much hydrophobic and hydrophilic residuals can be
wiped off. Higher the percentage, the better the stain resistance.
Example 5 exhibits better stain resistance.
[0432] It should be apparent that embodiments and equivalents other
than those expressly discussed above come within the spirit and
scope of the present invention. Thus, the present invention is not
limited by the above description but is defined by the appended
claims.
* * * * *